The following text and tables are arranged according to the branching order of clades in the four-gene backbone and Supermatrix analyses (Figs. 1 and 2, respectively). The synonymy shown is incomplete but includes obligate synonyms that are needed to trace names to their basionym, a few facultative synonyms, synonyms that are invalid or illegitimate and misapplied names.

Hygrophoraceae subfam. Hygrocyboideae Padamsee & Lodge, subf. nov.

MycoBank MB804066.

Type genus: Hygrocybe (Fr.) P. Kumm., Führ. Pilzk. (Zwickau): 111 (1871).

≡ Hygrophorus subg. Hygrocybe Fr., Summa veg. Scand., Section Post. (Stockholm): 308 (1849).

Basidiomes fleshy; colors usually bright, rarely dull; lamellae, usually thick, yielding a waxy substance when crushed, rarely absent; true veils lacking, rarely with false peronate veils formed by fusion of the gelatinous ixocutis of the pileus and stipe, and fibrillose partial veils formed by hyphae emanating from the lamellar edge and stipe apex; basidiospores thin-walled, guttulate, hyaline (though species with black staining basidiomes may have fuscous inclusions), smooth or ornamented by conical spines, inamyloid, acyanophilous; basidia guttulate, mono- or dimorphic, if dimorphic then basidia emanating from the same fascicle differing in length and width; mean ratio of basidia to basidiospore length 3–7; pleurocystidia absent; pseudocystidia sometimes present; true cheilocystidia usually absent but cystidia-like hyphoid elements emanating from the lamellar context or cylindric or strangulated ixo-cheilocystidia embedded in a gelatinous matrix sometimes present; lamellar trama inamyloid, regular or subregular but not highly interwoven, divergent or pachypodial; comprised of long or short hyphal segments with oblique or perpendicular cross walls, often constricted at the septations, usually thin-walled but hyphae of the central mediostratum sometimes slightly thickened. Pileipellis structure a cutis, disrupted cutis, ixocutis, ixotrichodermium or trichodermium, but never hymeniform; clamp connections present or absent; habit terrestrial, rarely on wood or arboreal, often associated with mosses, growing in forests or grasslands; possibly biotrophic but not known to form ectomycorrhizae with woody plants.

Phylogenetic support

Support for a monophyletic clade representing subf. Hygrocyboideae was high in the 4-gene backbone (99 % MLBS, Fig. 1; 1.0 B.P. Online Resource 6), and Supermatrix (80 % MLBS, Fig. 2) analyses, but fell below 50 % in the LSU and ITS-LSU analyses (Figs. 3 and 5). The ITS analysis by Dentinger et al. (unpublished) shows 98 % MLBS support for subf. Hygrocyboideae. Support for subf. Hygrocyboideae as the sister clade to subf. Hygrophoroideae was highest in the Bayesian 4-gene backbone analysis (1.0 PP), while bootstrap support was moderately high in all the ML analyses except the LSU (78 % Supermatrix, and 77 % 4-gene backbone). Moncalvo et al. (2002) found Bayesian support for two sister clades, one with Hygrocybe and Chromosera and another with Hygrophorus and Chrysomphalina, and Lodge et al. (2006) recovered the same topology without support, but the topology was more complex in the Supermatrix analysis by Matheny et al. (2006).

Fig. 3 LSU analysis (LROR–LR5) of Hygrophoraceae together with representatives of the hygrophoroid clade (Sarcomyxa and Xeromphalina) and several outgroups (Mycena and Omphalina), rooted with Macrotyphula phacorrhiza. ML bootstrap values ≥ 50 % appear above the branches. Heavily bolded branches have ≥ 70 % and lightly bolded branches have 50–69 % ML bootstrap support Full size image

Tribes included

Hygrocybeae, Humidicuteae, stat. nov. and Chromosereae, tribe nov.

Hygrophoraceae [subfam. Hygrocyboideae ] tribe Hygrocybeae Kühner, Bull. Soc. Linn. Lyon 48: 621 (1979)

Type genus: Hygrocybe (Fr.) P. Kumm., Führ. Pilzk. (Zwickau): 26 (1871).

Emended here by Lodge

Basidiomes lacking carotenoid pigments, typically with betalain, DOPA based compounds that usually appear as bright colors (muscaflavin, flavohygrocybin, rhodohygrocybin), but these sometimes converted to fuscous forms, or as colorless forms (hygroaurin, formed by conjugation of muscaflavin with amino acids) or pigments completely absent; true veils lacking but rarely with false peronate veils formed by fusion of the gelatinous ixocutis of the pileus and stipe, and fibrillose partial veils formed by hyphae emanating from the lamellar edge and stipe apex; lamellae usually present, thick, yielding a waxy substance when crushed; basidiospores thin-walled, guttulate in KOH mounts, hyaline, sometimes with fuscous inclusions in staining species, smooth or rarely ornamented by conical spines, inamyloid, acyanophilous, non-metachromatic; basidia guttulate, mono- or dimorphic, if dimorphic then basidia emanating from the same fascicle differing in length and often width; mean ratio of basidia to basidiospore length 3–7; context not dextrinoid; pleurocystidia absent; pseudocystidia may be present, true cheilocystidia usually absent but cystidia-like hyphoid elements emanating from the lamellar context commonly present, rarely with true cheilocystidia; lamellar trama regular to subregular, never divergent, pachypodial or highly interwoven; clamp connections usually present in context and hymenium unless spores are ornamented with spines or basidia bisporic; clamps normal or medallion type, rarely toruloid; habit terrestrial, bryophilous, rarely on wood or arboreal, growing in forests or grasslands; possibly biotrophic, cloned from the rhizosphere but not plant roots, not forming ectomycorrhizae with woody plants.

Phylogenetic support

Support for Tribe Hygrocybeae is strong in our LSU (85 % MLBS, Fig. 3), 4-gene backbone (98 % MLBS & 1.0 B.P. Fig. 1 and Online Resource 6), and Supermatix (96 % MLBS, Fig. 2) analyses. Dentinger et al. (unpublished) show 93 % MLBS support for tribe Hygrocybeae in their ITS analysis. Previous studies show similarly high support for a monophyletic Hygrocybeae using a maximum parsimony analysis of LSU (98 % MPBS, Moncalvo et al. 2002), ITS (100 % MPBS, Seitzman et al. 2011) and a multigene analysis (100 % MLBS and 1.0 B.P. Matheny et al. 2006) but none of those analyses included Hygroaster.

Genera included

Hygrocybe and Hygroaster.

Comments

As noted by Bas (1990), the citation by Arnolds (1990) as tribe Hygrocybeae (Kühner) Bas & Arnolds was incorrect because only names at or below genus are recombined (Art. 6.7), so authors of higher taxa remain the same when they are transferred to another position. Bas (1990) and Arnolds (1990) treated tribe Hygrocybeae in the Tricholomataceae instead of Hygrophoraceae.

Hygrocybe (Fr.) P. Kumm., Führ., Pilzk. (Zwickau): 26 (1871)

≡ Hygrophorus subg. Hygrocybe Fr. (1849).

Type species: Hygrocybe conica (Schaeff.) P. Kumm., Führ. Pilzk. (Zwickau): 111 (1871)

≡ Hygrophorus conicus (Schaeff.) Fr., Epicr. syst. mycol. (Upsaliae): 331 (1838) [1836–1838],

≡ Agaricus conicus Schaeff., Fung. Bavar. Palat. 4: 2 (1877)].

Characters as in tribe Hygrocybeae. Differing from Hygroaster in usually having bright pigments, and basidiospores that are typically smooth, but if conical warts are present, the spores are broadly ellipsoid rather than globose or subglobose and the outline is usually subangular.

Phylogenetic support

Hygrocybe s.s. is strongly supported as monophyletic in our 4-gene backbone (95 % MLBS, 1.0 B.P. Fig. 1 and Online Resource 6), LSU (87 % MLBS, Online Resource 7) and ITS-LSU analyses (90 % MLBS, Fig. 4); support is lower in our Supermatix analysis (60 % MLBS; Fig. 2). Previously, Moncalvo et al. (2002) found a monophyletic Hygrocybe using LSU, but it lacked significant BS support. Others subsequently showed 100 % BS or 1.0 Bayesian PP support for a monophyletic Hygrocybe including Binder et al.’s (2010) six gene analysis (RAxML and Bayesian), Lawrey et al.’s (2009) ITS-LSU (ML and MP), Matheny et al.’s multigene Supermatrix (MP and Bayesian), Seitzman et al.’s (2011) ITS (MP) and Vizzini et al.’s (2012) ITS-LSU (ML, MP and Bayesian). Babos et al. (2011) found lower support using only ITS (70 % MLBS). We find high support for Hygrocybe as the sister clade to Hygroaster in the 4-gene backbone (98 % ML BS, 1.0 B.P. and Supermatrix analyses (96 % MLBS).

Fig. 4 Tribe Hygrocybeae (Group 1) ITS-LSU analysis, rooted with Hygroaster albellus. Genes analyzed were ITS (ITS1, 5.8S & ITS2), LSU (LROR-LR5). Presence of betalain (DOPA based) and carotenoid pigments and presence of clamp connections in forms with 4-spored basidia are denoted by filled circles while empty circles denote their absence. Lamellar trama types are: R for regular (parallel) and S for subregular. ML bootstrap values ≥ 50 % appear above the branches. Heavily bolded branches have ≥ 70 % and lightly bolded branches have 50–69 % ML bootstrap support Full size image

Subgenera included

Hygrocybe s.s. is currently treated as comprising two subgenera, Hygrocybe and Pseudohygrocybe. Other subgenera that have previously been included in Hygrocybe s.l. are treated as segregate genera here but are listed in Table 1.

Comments

The name Hygrocybe was not validly published in Fries (1821) or (1838), but was validated as Hygrophorus subgen. Hygrocybe in Fries (1849). Though Rabenhorst (1844) pre-dates this, he did not list Hygrocybe among the infrageneric names he accepted, which indicates he rejected them as synonyms of genus Agaricus, [unranked] Hygrophorus, [unranked] Hygrocybe (pers. com. Shaun Pennycook, 28 Oct. 2010 to S.A. Redhead). Kummer (1871) was thus the first to validly use Hygrocybe Fr. at genus rank. Kovalenko (1988) treated the current subgenera as separate genera: Hygrocybe and Pseudohygrocybe (Bon) Kovalenko. Herink (1959) previously attempted to separate the two main Hygrocybe groups at genus rank using Godfrinia Maire (1902), nom. illeg., with type species G. conica (Scop. ex Fr.) R. Maire, and an emended Hygrocybe. Except for inclusion of H. punicea, Maire’s (1902) “Godfrinia” illeg. is concordant with the current Hygrocybe subg. Hygrocybe. Because “Godfrinia” (1902) is predated by Hygrocybe (Kummer 1871) and shares the same type species, it is superfluous and therefore illegitimate (Art. 52.10). Heim (1936) named a new genus, Bertrandia, to accommodate a conical blackening species from Africa that exudes copious latex when cut, but the type species is now correctly classified as Hygrocybe astatogala (Heim) Heinem. (1963) in subg. Hygrocybe [sect. Hygrocybe] subsect. Hygrocybe, rendering Bertrandia a synonym of Hygrocybe. Although the composition of Herink’s (1959) emended Hygrocybe (H. miniata, H. coccinea, H. marchii, H. miniato-alba and H. turunda) corresponds to the current subg. Pseudohygrocybe, he was incorrect in attempting to replace the type species of Hygrocybe (H. conica) with H. miniata. Babos et al. (2011) erroneously reported that Candusso (1997) transferred Hygrocybe to the Agaricaceae, apparently mistaking the early history of the Hygrophoraceae (pp. 33–44), in which all agaric species were first placed in Agaricus by Scopoli, Schaeffer and Fries, for the classification accepted by Candusso (pp. 313–323).

As delineated by Fries (1849) and Bataille (1910), Hygrocybe included terrestrial species with a pileus that was thin, tender, sometimes striate, with a moist, lubricous or viscid surface; stipe hollow or stuffed, splitting or fibrillose, generally smooth at the apex, with a moist or viscid surface. Hygrocybe species are frequently brightly colored, though gray-brown ones also occur. DOPA betalain pigments are found throughout the pigmented Hygrocybe ss, but rarely outside this group, while carotenoid pigments are apparently absent from Hygrocybe s.s. (Table 3, Online Resource 4). As in other members of the family, the lamellae of Hygrocybe are waxy and yield an oily substance when crushed (Young 1997), and they are usually but not always thick (Lodge et al. 2006). The lamellar trama structure is always regular or subregular in Hygrocybe s.s. and s.l., differentiating it from the typically interwoven arrangement in Cuphophyllus, the divergent trama in Hygrophorus, and the pachypodial arrangement in Chrysomphalina and Haasiella (Norvell et al. 1994) and now Aeruginospora (Table 3). The hyphae typically have clamp connections. The basidiospores of Hygrocybe s.s. and s.l. are always hyaline, inamyloid, thin-walled, and typically smooth but occasionally with conical warts. While most Hygrocybe s.s. and s.l. are terrestrial, often growing in grasslands in Europe and forests in North America and the tropics, a few tropical species are now known to be arboreal (e.g., H. hapuuae Desjardin and Hemmes 1997; H. pseudoadonis S.A. Cantrell and Lodge 2004; and H. rosea, Lodge et al. 2006). Although they appear to be biotrophic based on isotopes, their biotic relationships are enigmatic (Seitzman et al. 2011). Hygrocybe have been sequenced from the rhizosphere of plant roots (see Ecology section), which may explain how they obtain plant carbon.

Table 3 Synoptic key to the Hygrophoroid clade. Substrata reported are: bryophytes (b), debris (d), ectomycorrhizal hosts (e), ferns (f), grasses (g), lichenized with chlorophyta (lch) or cyanobacteria (lcy), soil (s), humus (h), and wood (w). Characters are noted as present (+), absent (−), or if variable the predominant form is presented first (+/− or −/+) Full size table

Hygrocybe subgen. Hygrocybe [autonym] (1976).

Type species: Hygrocybe conica (Schaeff.) P. Kumm., Führ. Pilzk. (Zwickau): 111 (1871),

≡ Hygrophorus conicus (Schaeff.) Fr., Epicr. syst. mycol. (Upsaliae): 331 (1838) [1836–1838],

≡ Agaricus conicus Schaeff., Fung. Bavar. Palat. 4: 2 (1877).

Pileus usually colored red, orange, yellow, green or purple from DOPA based betalain pigments, rarely colorless or fuscous with age or bruising from transformation of DOPA; fibrillose or glutinous partial veils occasionally present; lamellae usually free or narrowly attached, rarely broadly attached by a decurrent tooth; lamellar trama hyphae strictly parallel, usually with tapered ends and exceeding 140 μm (some > 1000 μm) in length, unless the basidia and spores are dimorphic; basidia usually 3–5 times the length of their basidiospores, vs > 5 times in subg. Pseudohygrocybe (Table 3).

Phylogenetic support

Subg. Hygrocybe is strongly supported as a monophyletic clade in two of our analyses without inclusion of H. helobia (100 % MLBS in the Supermatrix, 100 % MLBS and BPP in the 4-gene backbone analyses, Fig. 1 and Online Resource 6), but only weakly supported by analyses of ITS-LSU (53 % MLBS, Fig. 4), and LSU (54 % & 32 % MLBS, Fig. 3 and Online Resource 7). Previous analyses using fewer species found strong support for a monophyletic subg. Hygrocybe (100 % MLBS in the multigene analysis by Matheny et al. 2006; 95 % MPBS in the LSU analysis by Moncalvo et al. 2002; 96 % support in the analysis of mostly ITS data by Seitzman et al. 2011). Support for a monophyletic subg. Hygrocybe using ITS sequences alone is not significant for the two spp. in Babos et al. (2011), our 24 spp. (37 % MLBS, Online Resource 8) but high for the 18 spp. in Dentinger et al. (unpublished data, 83 % MLBS).

Sections included

Type section Hygrocybe; includes existing sections Chlorophanae and Microsporae, and new sections Pseudofirmae and Velosae.

Comments

Our various phylogenetic analyses, as detailed below, reveal six clades or segments of grades of which four are concordant with currently named sections and subsections. These are sect. Hygrocybe with subections Hygrocybe and Macrosporae R. Haller Aar. ex Bon, sect. Chlorophanae (Herink) Arnolds ex Candusso, and sect. Microsporae Boertm. In addition, we describe two new sections to accommodate monophyletic clades that comprise most of the species with dimorphic spores and basidia, which were previously assigned to sect. Firmae. The position of H. helobia is unstable among analyses, but it also belongs in subg. Hygrocybe.

Hygrocybe [subgen. Hygrocybe ] sect. Hygrocybe. [autonym] (1889).

Type species: Hygrocybe conica (Schaeff.) P. Kumm., Führ. Pilzk. (Zwickau): 111 (1871)

≡ Hygrophorus conicus (Schaeff.) Fr., Epicr. syst. mycol. (Upsaliae): 331 (1838) [1836–1838],

≡ Agaricus conicus Schaeff., Fung. Bavar. Palat. 4: 2 (1877).

Pileus conical or conico-campanulate; lamellae free or narrowly attached; lamellar trama hyphae parallel, some 200 μm in length, with tapered ends and oblique septa.

Phylogenetic support

Sect. Hygrocybe support varies from high in our 4-gene backbone analysis (97 % MLBS and 100 % BPP; Fig. 1 and Online Resource 6), ITS-LSU analyses (93 % MLBS and 87 % MPBS including H. noninquinans (a replacement name for H. konradii var. antillana, 55 % MLBS and 87 % MPBS excluding it; Fig. 4) and ITS (77 % MLBS, Online Resource 8) to low in our Supermatrix and Hygrocybe LSU and ITS analyses (Fig. 2, Online Resources 8). A previous ITS analysis by Seitzman et al. (2011) shows 96 % MLBS support while the ITS analysis by Babos et al. (2011) shows 83 % neighbor joining (NJ) BS and 79 % MLBS support for sect. Hygrocybe.

Subsections included

Type sect. Hygrocybe; includes subsect. Macrosporae.

Hygrocybe [subg. Hygrocybe sect. Hygrocybe ] subsect. Hygrocybe [autonym].

[= subsect. “Nigrescentes” (Bataille) Arnolds, invalid as the type species of the genus is included (Art. 22.2)].

Type species: Hygrocybe conica (Schaeff.) P. Kumm., Für Pilzk. (Zwickau): 111 (1871)

≡ Hygrophorus conicus (Schaeff.) Fr., Epicr. syst. mycol. (Upsaliae): 331 (1838),

≡ Agaricus conicus Schaeff., Fung. Bavar. Palat. 4: 2 (1877).

Characters as in sect. Hygrocybe; pileus surface sometimes fibrillose. Usually differs from subsect. Macrosporae in presence of black staining reactions and fibrillose pileus.

Phylogenetic support

This subsection was moderately to highly supported by the various phylogenetic analyses. Support is highest in the Supermatrix (92 % MLBS) and LSU analyses (67 % and 89 % MLBS; Figs. 2 and 3, Online Resource 7), and moderate in our ITS analysis (51 % MBS, Online Resource 8). Dentinger et al. (unpublished data) and Babos et al. (2011) also showmoderate to high support for the H. conica species complex (61 % MLBS, respectively and 98 % NJBS) using ITS sequences.

Species included

Type species: Hygrocybe conica (Schaeff.) P. Kumm. 1871. Species confirmed by molecular phylogenies include H. conica varieties, H. nigrescens var. brevispora, and H. singeri (A.H. Sm. & Hesler) Singer. Species placed here based on morphology alone include H. astatogala (R. Heim) Heinem., H. atrosquamosa Pegler and H. olivaceonigra (P.D. Orton) M.M. Moser. The status of other named species is unresolved as this group is in need of revision, including H. cinereifolia Court. & Priou, H. cuspidata (Peck) Murrill, H. riparia Kreisel, H. conicopalustris R. Haller Aar., H. pseudoconica J.E. Lange and H. veselskyi Singer & Kuhtan. Hygrocybe cortinata Heinem., described from Africa, closely resembles H. conica except for the presence of a cortinoid partial veil, so it likely belongs in subsect. Hygrocybe. Hygrocybe noninquinans is excluded based on the absence of black staining reactions, a silky-fibrillose pileus surface, and placement at the base of subsect. Macrosporae in the Supermatrix analysis; H. spadicea may also belong in subsect. Macrosporae.

Comments

This subsection is often referred to as the staining conica group as all of the confirmed species have blackish staining reactions and a conic or cuspidate pileus, the surface sometimes with coarse fibrils or appressed squamules. Hygrocybe cuspidata (Peck) Roody is a blackening species described from eastern North America, but the name has been misapplied to collections from Europe of H. acutoconica in the non-staining conica group under the name H. acutoconica var. cuspidata (Peck) Arnolds (1985a) (see Boertmann 2010). The Japanese H. conica sequences comprise a distinct clade in our ITS analysis (88 % MLBS). The type species, H. conica, has micromorphology that is typical of subg. Hygrocybe including parallel lamellar trama hyphae that are long and tapered at the ends with oblique septa (Fig. 5). The longest hyphae are rare and are best viewed by teasing the trama hyphae apart in smash mounts.

Fig. 5 Hygrocybe (subg. Hygrocybe) sect. Hygrocybe. Hygrocybe conica lamellar cross section (DJL05TN89). Scale bar = 20 μm Full size image

Hygrocybe [subg. Hygrocybe sect. Hygrocybe ] subsect. Macrosporae R. Haller Aar. ex Bon, Doc. Mycol. 24(6): 42 (1976).

Type species: Hygrocybe acutoconica (Clem.) Singer (1951) [as H. acuticonica Clem.]

≡ Mycena acutoconica Clem., Bot. Surv. Nebraska 2: 38 (1893),

= Hygrocybe persistens (Britzelm.) Singer (1940),

≡ Hygrophorus conicus var. persistens Britzelm. (1890)].

Characters of sect. Hygrocybe; lacking dark staining reactions, though the stipe base may slowly stain gray; surface usually radially fibrillose-silky and viscid or glutinous but some with dry surface even when young; some spore lengths exceed 10 μm. Differs from subsect. Hygrocybe in absence of dark staining reaction and often a smoother pileus surface texture.

Phylogenetic support

Strong support for subsect. Macrosporae is shown in our ITS analysis (99 % MLBS, with 77 % support as the sister clade to subsect. Hygrocybe; Online Resource 8). Support for this subsection in our other analyses varies depending on whether species in the basal part of the grade are included or excluded. The Hygrocybe acutoconica complex, including H. acutoconica (Clem.) Singer var. acutoconica, collections of this variety from Europe previously referred to as H. persistens (Britzelm.) Singer, and H. acutoconica f. japonica Hongo, form a strongly supported clade (99 % ML and 100 % MPBS in the ITS-LSU; 99 % MLBS in the ITS), but with weaker support in the Supermatrix analysis (63 % MLBS). Placement of H. spadicea is ambiguous, with strongest support for inclusion in subsect. Macrosporae using ITS (99 % MLBS), ambiguous placement using LSU (Fig. 3 and Online Resource 7) and basal to both subsect. Hygrocybe and Macrosporae in the Supermatrix analysis (Fig. 2). Similarly, both Babos et al. (2011) and Dentinger et al. (unpublished data) show ambiguous placement of H. spadicea lacking significant BS support. In our ITS analysis, H. noninquinans is basal to both subsections (69 % ML BS) making subsect. Macrosporae paraphyletic if included. Similarly, including H. noninquinans makes subsect. Macrosporae paraphyletic in our ITS-LSU analysis as a species in the staining conica group (subsect. Hygrocybe) falls between H. noninquinans and other non-staining spp. with high BS support. The 4-gene backbone analysis places H. noninquinans with H. aff. conica in sect. Hygrocybe with high support (97 % ML, 1.0 BPP), while the Supermatrix places it as a basal member in sect. Macrosporae but with low support (Supermatrix, 24 % MLBS). In an ITS analysis by Dentinger et al. (unpublished data), however, H. noninquinans (as H. konradii var. antillana) is basal to subsect. Conica with low support as part of a paraphyletic grade corresponding to subsect. Macrosporae. Hygrocybe subpapillata is unplaced in our ITS analysis, but is basal to spp. in sect. Pseudofirmae and sect. Macrosporae in an ITS analysis by Dentinger et al. (unpublished data).

Species included

Type species: H. acutoconica. All of the varieties of H. acutoconica are included. Hygrocybe persistens (Britzelm.) Singer is currently considered a synonym of H. acutoconica (Boertmann 2010; Cantrell and Lodge 2000), as is H. subglobispora P.D. Orton (Boertmann 2010). Hygrocybe spadicea P. Karst. is tentatively included based on high support in our ITS analysis, though support for inclusion is weak or ambiguous in our other analyses and Dentinger et al.’ (unpublished) ITS analysis, and the fibrillose pileus surface which fits better in subsect. Hygrocybe. Hygrocybe noninquinans is included based on its similarities to H. acutoconica var. konradii, and its placement basal to other species of sect. Macrosporeae in our Supermatrix analysis. Hygrocybe zuluensis Boertmann is included based on morphology.

Comments

This subsection is often referred to as the non-staining conica group. Boertmann (2010) regards H. konradii as a wide-spored variety of H. acutoconica. The ITS analysis by Dentinger et al. (unpublished), however, suggests that while there are wide-spored collections embedded in the H. acutoconica clade, there is also a well-supported sister clade to H. acutoconica comprised of H. konradii s.s. collections (100 % support for the clade, 77 % MLBS support as sister to H. acutoconica var. acutoconica). Hygrocybe noninquinans was described as H. konradii var. antillana, but it is raised here to species rank based on phylogenetic analyses that place it apart from H. konradii. The name H. antillana was occupied, so a new name is provided.

Hygrocybe noninquinans Lodge & S.A. Cantrell, nom. nov., stat. nov.

MycoBank MB804045.

Replaced synonym: Hygrocybe konradii var. antillana Lodge & Cantrell, Mycol. Res. 104(7): 877–878 (2000).

Type: PUERTO RICO, Mun. Río Grande, El Yunque National Forest (Caribbean National Forest), Caimitillo Trail, 16 Jun 1997, CFMR-PR 4555, CFMR.

Hygrocybe [subg. Hygrocybe ] sect. Velosae Lodge, Ovrebo & Padamsee, sect. nov.

MycoBank MB804047.

Type species: Hygrophorus hypohaemactus Corner, Trans. Br. Mycol. Soc. 20(2): 180, Figs. 5, 6, 8a (1936)

≡ Hygrocybe hypohaemacta (Corner) Pegler & Fiard, Kew Bull. 32(2): 299 (1978).

Pileus and stipe red or pink, covered in a thin to thick glutinous layer, glutinous layer of pileus and stipe surface connected, rupturing when pileus expands leaving an appendiculate gelatinous margin on the pileus and sometimes leaving a glutinous annulus on the stipe, resembling a peronate veil but the glutinous layer not separated from the pileus or stipe surface hyphae by a differentiated layer; lamellar trama hyphae fusiform, with tapered ends and oblique septa, some exceeding 140 μm in length; lamellar edge with pseudocystidia originating in the context, swollen, containing many vacuoles with oleaginous contents, sometimes with glutinous coating, simple or branched, projecting from the lamellar margin where they intertwine with similar but less vacuolated structures emanating from the stipe apex above the glutinous zone, these structures forming an arachnoid connection between the lamellae and stipe; sometimes hyphal strands connecting the pileus margin and stipe leave a fibrillose layer above the glutinous annulus; annulus sometimes obscure; basidia and spores dimorphic: macrobasidia clavate or somewhat capitate-stipitate, 4-sterigmate, with oleaginous contents and basal clamp connection; microbasidia clavate; basidiospores globose, subglobose to broadly ellipsoid.

Etymology

Velo-veil, referring to the fibrillose and glutinous partial veil.

Phylogenetic support

Our Supermatrix (Fig. 2) and Hygrocybe LSU analyses (Online Resource 7) place H. roseopallida in the same clade with H. hypohaemacta and H. aff. hypohaemacta from the neotropics, but with low bootstrap values. Lodge and Ovrebo (2008) show stronger support (76 % MLBS) for a monophyletic H. roseopallida – H. hypohaemacta clade using ITS and LSU sequences; its inclusion in sect. Pseudofirmae has low support (53 %). In the 4-gene backbone analysis there is 100 % MLBS (0.9 B.P. support for placing the H. hypohaemacta clade apart from the Pseudofirmae clade (H. appalachianensis). In both the ML and Bayesian backbone analyses, H. hypohaemacta (sect. Velosae) falls between. sect. Hygrocybe on one side. and H. glutinipes (sect. Chlorophanae) and sect. Pseudofirmae on the other side. The ITS-LSU analysis (Fig. 4) has a well-supported sect. Pseudofirmae clade (96 % MLBS, 93 % MPBS) that excludes H. hypohaemacta; instead, H. hypohaemacta appears basal to sect. Chlorophanae. The Supermatrix analysis has high support for paleotropical H. hypohaemacta (LSU only) and neotropical H. afn hypohaemacta as sister species (77 %) but Dentinger (personal comm.) shows higher support (99 % MLBS) in an LSU analysis. Our Hygrocybe LSU analysis has moderate support (62 % MLBS; Online Resource 7) for placing H. aff. hypohaemacta and H. hypohaemacta together. In our 4-gene backbone analyses (Fig. 1 and Online Resource 6) and our ITS analysis, H. hypohaemacta appears in a grade with H. glutinipes, but H. glutinipes is included in sect. Chlorophana in our Supermatrix analysis, far from H. hypohaemacta.

Species included

Type species: Hygrocybe hypohaemacta. Inclusion of two neotropical species, H. aff. hypohaemacta and H. roseopallida Ovrebo & Lodge, is phylogenetically and morphologically supported.

Comments

Singer (1986) placed H. hypohaemacta in subg. Hygrocybe owing to the regular lamellar trama composed of long, fusiform elements – a placement confirmed by our molecular phylogenies. Others, including Pegler and Fiard (1978) and Lodge and Pegler (1990) placed H. hypohaemacta in subg. Pseudohygrocybe sect. Firmae, though Cantrell and Lodge (2004) noted the resemblance of trama structure to subg. Hygrocybe and suggested that molecular phylogenies were needed to resolve placement. Neotropical collections identified as H. hypohaemacta will need a new name as the spores differ somewhat in shape and size and the LSU sequences diverge by 12.6 % from the SE Asian sequence. Hygrocybe roseopallida is included in sect. Velosae based on moderate molecular support and shared characters, i.e., subglobose to broadly ellipsoid macro- and microspores, a glutinous peronate pseudoveil, cortinoid connections between the lamellar edge and stipe apex partly formed by vacuolated pseudocystidia emanating from the lamellar edge (Lodge and Ovrebo 2008). Although Corner (1936) stated that the glutinous layer of the pileus margin was not connected to the stipe in H. hypohaemacta, a projecting glutinous margin is visible on the pileus, a vague glutinous annulus is visible in photos of the H. hypohaemacta collection from Malaysia that was sequenced, and a glutinous annulus can be seen in a photo of H. aff. hypohaemacta from Puerto Rico (Fig. 25 insert). Pseudocystidia emanating from the lamellar edge in both H. aff. hypohaemacta and H. roseopallida that form the inner fibrous portion of the veil are shown in Fig. 6. Inner fibrous and outer glutinous veil elements were clearly visible in the type and other collections of H. roseopallida (Lodge and Ovrebo 2008).

Fig. 6 Hygrocybe (subg. Hygrocybe) sect. Velosae. Pseudocystidia emanating from the lamellar edge, which contributes to an inner, fibrous pseudoveil: a. Hygrocybe aff. hypohaemacta (BZ-1903); b. Hygrocbe roseopallida (type). Scale bar = 20 μm Full size image

Hygrocybe [subg. Hygrocybe ] sect. Pseudofirmae Lodge, Padamsee & S.A. Cantrell, sect. nov.

MycoBank MB804048.

Type species: Hygrophorus appalachianensis Hesl. & A.H. Sm. North American Species of Hygrophorus: 147 (1963),

≡ Hygrocybe appalachianensis (Hesl. & A.H. Sm.) Kronaw. (as ‘appalachiensis’), in Kronawitter & Bresinsky, Regensb. Mykol. Schr. 8: 58 (1998).

Pileus usually viscid or glutinous, often perforated in the center. Basidiospores and basidia dimorphic; ratio of macrobasidia to macrospore length usually < 5, macrobasidia expanded in upper part, typically broadly clavate or clavate-stipitate; lamellar trama hyphae parallel, long or short, with or without oblique septa; pileipellis a cutis, disrupted cutis or trichoderm, overlain by a thin to thick ixocutis which if ephemeral then leaves a thin patchy gelatinous coating on the cuticular hyphae.

Etymology

Pseudo = false, firmae – referring to sect. Firmae.

Phylogenetic support

Support for a monophyletic sect. Pseudofirmae, including H. rosea, is strongest in the ITS-LSU analysis (96 % MLBS and 93 % MPBS; Fig. 4). ITS support is high (94 % MLBS, not shown) for the clade comprising H. appalachianensis, H. chloochlora, H. aff. chloochlora and H. aff. prieta, but declines to 42 % MLBS if H. rosea is included; H. occidentalis, H. cf. neofirma and H. trinitensis are placed in a neighboring clade with low support. A similar paraphyletic grade topology is shown in our ITS analysis (Online Resource 8), but our Hygrocybe LSU (Online Resource 7) shows Pseudofirmae as monophyletic. Similarly, an LSU analysis by Dentinger (pers. com.) shows sect. Pseudofirmae as a single clade comprised of H. appalachianensis, H. occidentalis and H. rosea, but with high support (94 % MLBS). Our Supermatrix analysis also has high support for the Pseudofirmae clade (96 % MLBS; Fig. 2), but the type of sect. Microsporae (Hygrocybe aff. citrinovirens) is embedded close to the base, possibly from long-branch attraction though the ITS analysis by Dentinger et al. (unpublished) also shows the same topology; H. rosea is not included in Dentinger et al.’s ITS and LSU analyses.

Species included

Type species: Hygrocybe appalachianensis (Hesler & A.H. Sm.) Kronaw. Hygrocybe chloochlora, H. occidentalis, H. cf. neofirma (MCA-1721), H. aff. neofirma (BZ-1926), H. aff. prieta, H. rosea and H. trinitensis (Dennis) Pegler are included here based on both molecular and micromorphological data. The following species are included based on macrobasidia morphology: H. amazonensis Singer, H. brunneosquamosa Lodge & S.A. Cantrell, H. campinaranae Singer, H. chamaeleon (Cibula) D.P. Lewis & Ovrebo, H. cheilocystidiata Courtec., H. cinereofirma Lodge, S.A. Cantrell & T.J. Baroni, H. earlei (Murrill) Pegler, H. flavocampanulata S.A. Cantrell & Lodge, H. guyanensis Courtec., H. helvolofirma Pegler, H. hondurensis Murrill, H. laboyi S.A. Cantrell & Lodge, H. lutea (Beeli) Heinem., H. megistospora Singer, H. miniatofirma S.A. Cantrell & Lodge, H. mississippiensis D.P. Lewis & Ovrebo, H. naranjana Pegler, H. neofirma Lodge & S.A. Cantrell, H. nouraguensis Courtec., H. olivaceofirma Lodge, S.A. Cantrell & Nieves-Riv. and Hygrophorus alutaceus Berk. & Broome.

Comments

Species in sect. Pseudofirmae, such as H. appalachianensis, often have staggered development of the macro- and microbasidia. The holotype of H. appalachianensis was not fully mature, and the description of basidia was only for microbasidia while the immature macrobasidia were described as pleurocystidia. There were mature macrobasidia in the holotype on the lamellae close to the juncture of the stipe and pileus, which accounts for the macrospores that were described; the microspores, however, were present but ignored.

Hygrocybe rosea was found upon re-examination to have weakly dimorphic basidia and spores, consistent with phylogenetic placement as a basal species in sect. Pseudofirmae. Macrobasidia in all of the species in the H. appalachianensis clade are clavate-stipitate (Fig. 7) while those in the H. occidentalis–H. neofirma clade are clavate and expand gradually toward the apex (Fig. 8), so they might eventually be accorded status of subsections in Pseudofirmae. Macrobasidia of sect. Pseudofirmae are clavate or clavate-stipitate whereas those of H. firma, which is now placed in subg. Pseudohygrocybe, are cylindric to narrowly clavate. Furthermore, the ratio of macrobasidia to macrospore length is generally less than 5 in Pseudofirmae, as typical of subg. Hygrocybe, and exceeds 5 in H. firma, typical of subg. Pseudohygrocybe. Further revision of sect. Pseudofirmae with greater taxon sampling for molecular analyses is needed. Hygrophorus alutaceus was erroneously listed as a synonym of Hygrocybe firma by Pegler (1986) because it bears the same collection number (Petch 880) as the type of H. firma, but the diagnoses described the pileus as glabrous in H. alutaceus whereas the pileus of H. firma was described as tomentose. Annotation of the type of H. alutaceus by DJL and SAC shows the macrobasidia are broadly clavate (39–46 × 10.7–18 μm) and the pileipellis is a repent ixocutis, unlike the type of H. firma with narrowly clavate macrobasidia of (36–60 × 6.4–7.2 μm), and a disrupted cutis transitioning to a trichodermium that is lacking gelatinization.

Fig. 7 Hygrocybe (subg. Hygrocybe) sect. Pseudofirmae. Hygrocybe appalachianensis lamellar cross section, showing macrobasidia rooted more deeply in the hymenium than the microbasidia (Roody, DMWV00-953). Scale bar = 20 μm Full size image

Fig. 8 Hygrocybe (subg. Hygrocybe) sect. Pseudofirmae. Hygrocybe neofirma (M.C. Aime, Guyana): a. pileipellis; b. macrospores; c. microspores; d. microbasidium; e. macrobasidium. Hygrocybe occidentalis (E. Cancerel, Puerto Rico): f. macrospores; g. microspores; h. microbasidium; i. macrobasidium. Scale bar = 20 μm Full size image

Hygrocybe [subg. Hygrocybe ] sect. Microsporae Boertm., The genus Hygrocybe. Fungi of Northern Europe (Greve) 1: 16 (1995).

Type species: Hygrocybe citrinovirens (J.E. Lange) Jul. Schäff., Ber. bayer. bot. Ges. 27: 222 (1947) [≡ Camarophyllus citrinovirens J.E. Lange, Dansk Botanisk Arkiv 4(4): 20 (1923)].

Pileus conical or conico-campanulate, surface dry and appressed tomentose, squamulose or loosely fibrillose, red, orange or yellow; basidiospores mostly less than 10 μm long; pileipellis a trichoderm at least in the center.

Phylogenetic support

Support for a monophyletic sect. Microsporae (H. citrinovirens, H. intermedia and an H. intermedia-like collection from Tennessee labeled H. aff. citrinovirens) is strong in our ITS analysis (73 % MLBS, Online Resource 8). These species plus H. helobia appear as a paraphyletic grade in the ITS analysis by Dentinger et al. (unpublished data). Support for placing H. helobia in subg. Hygrocybe using ITS sequences is strong in Dentinger et al. (unpublished), weak in our analysis (Online Resource 8), its position is unstable among analyses and it has decurrent rather than adnexed to free lamellae, so we leave it unplaced.

Species included

Type species: H. citrinovirens. Hygrocybe intermedia and H. aff. citrinovirens from Tennessee are included based on molecular and morphological data and H. virescens (Hesler & A.H. Smith) Montoya & Bandala is included based on morphological data.

Comments

Though some spores in H. intermedia are up to 13 μm long, most are less than 10 μm long, the pileipellis is similar to that of the type, and phylogenetic support for the clade is strong so it is included here. Hygrocybe aff. citrinovirens differs from H. intermedia only in having a smooth instead of a fibrillose stipe, but ITS sequences places it closer to H. citrinovirens.

Hygrocybe [subg. Hygrocybe ] sect. Chlorophanae (Herink) Arnolds ex Candusso, Hygrophorus. Fungi europ. (Alassio) 6: 464 (1997),

= Godfrinia R. Maire em. Herink, sect. Ceraceae Herink, subsect. Chlorophaninae Herink, Acta. Mus. Bot. Sept. Lib. 1: 66 (1959).

Type species: Hygrocybe chlorophana (Fr. : Fr.) Wünsche, Die Pilze: 112 (1877)

≡ Agaricus chlorophanus Fr. : Fr., Syst. mycol. (Lundae) 1: 103 (1821).

Pileus viscid or glutinous, red, orange or yellow, stipe viscid or not, hymenophoral trama hyphae parallel, exceeding 200 μm in length, with tapered ends and oblique septa; pileipellis an ixocutis or ixotrichodermium.

Phylogenetic support

Support for the H. chlorophana – H. flavescens clade is strong in the Supermatrix, ITS and LSU analyses (100 % MLBS; Figs. 2 and 3). The 4-gene analyses place H. chlorophana as sister to the clade containing H. hypohaemacta (100 % MLBS and 1.0 BPP). Hygrocybe glutinipes appears as part of a grade near H. chlorophana in the Supermatrix, one of our LSU analyses (Fig. 3) and ours and Dentinger et al.’s (unpublished) ITS analyses with varying levels of support. Lodge and Ovrebo (2008) found different topologies for placing H. glutinipes with or apart from H. chlorophana, and bootstrap support for the two together of <50 % up to 86 %.

Species included

Type species: H. chlorophana. Possibly H. flavescens, if distinct from H. chlorophana; placement of H. glutinipes is ambiguous but it is tentatively included.

Comments

Hygrocybe flavescens (Kauffman) Singer was described from Michigan, and may be a distinct species, especially if it corresponds to the eastern North American clade labeled H. flavescens. In fact, one of the soil clones from Michigan (GU174284) matched the ITS sequences of specimens identified as H. flavescens. Hygrocybe flavescens is said to have a viscid stipe whereas H. chlorophana has a moist or dry stipe, but this character is not always reliable. A hybrid ITS sequence was found in a collection with a viscid stipe from the Great Smoky Mountain National Park despite a 9–12 % divergence in ITS sequences between the two clades (Hughes et al. 2010; in press). Hygrocybe glutinipes may be part of a grade within subg. Hygrocybe near H. chlorophana but is unstable in its position; it could be retained in sect. Chlorophanae based on morphology.

Species unplaced in subgen. Hygrocybe.

Hygrocybe glutinipes appears in a grade near H. hypohaemacta in the 4-gene backbone analyses, suggesting a relationship with sect. Velosae. Unlike spp. in sect. Velosae, H. glutinipes lacks a partial veil and has spores that are narrow and strangulated, so we regard it as unplaced.

Hygrocybe helobia resembles species in subg. Pseudohygrocybe, sect. Squamulosae, except that the long lamellar trama hyphae exceeding 400 μm indicate placement in subg. Hygrocybe (Boertmann 1995, 2010). Support for placing H. helobia in subg. Hygrocybe is strong in the ITS analysis by Dentinger et al., confirming Boertmann’s placement (1995, 2010). The position of H. helobia is unstable, however. Our ITS analysis places H. helobia as sister to sect. Microsporae, Dentinger et al.’s (unpublished) places it sister to H. intermedia and near H. citrinovirens, whereas our Supermatrix and LSU analyses place it with high support (90 %–100 % ML BS) in the H. miniata clade in subg. Pseudohygrocybe. The H. helobia clade appears to be a species complex that is strongly supported in our ITS analysis (91 % MLBS, Online Resource 8) as well as in the ITS analysis by Dentinger et al. (unpublished, 100 % MLBS).

Hygrocybe subgen. Pseudohygrocybe Bon, Doc. Mycol. 6 (24): 42 (1976).

Type species: Hygrocybe coccinea (Schaeff.) Fr., Epicr. syst. mycol. (Upsaliae): 330 (1838) [1836–1838],

≡ Agaricus coccineus Schaeff. Fung. Bavar. Palat. 4: 70 (1774),

≡ Pseudohygrocybe coccinea (Schaeff.: Fr.) Kovalenko (1988).

[NOT Agaricus coccineus Scop., Fl. carniol., (Wein) Edn. 2: 436 (1772), an earlier homonym of a sanctioned name]

Lamellar trama typically subregular, hyphal elements generally < 140 μm long, frequently <80 μm long, mostly with right-angled septations. Basidia and spores mostly monomorphic in size in one section and dimorphic in length in the other section, spore walls hyaline, usually smooth, rarely with spines; mean ratio of basidiospore to basidia length usually > 5. Basidiomes typically with bright DOPA based pigments, rarely colorless or with browning reactions from conversion of DOPA pigments.

Phylogenetic support

Subg. Pseudohygrocybe appears as a paraphyletic grade with the monophyletic subg. Hygrocybe clade on a long branch in our 4-gene backbone, Supermatrix, ITS-LSU analysis and ours and Seitzman et al.’s (2011) ITS analyses. Our LSU analysis of tribe Hygrocybeae (not shown), however, has strong support (87 % MLBS) for subg. Pseudohygrocybe as sister to subg. Hygrocybe. Similarly strong support for a monophyletic Pseudohygrocybe as sister to subg. Hygrocybe was previously found in a multigene Supermatrix analysis by Matheny et al. (2006, 100 % MLBS, 1.0 BPP). While the same sister-clade topology appears in our full LSU and our Hygrocybe LSU analyses, as well as in an LSU analysis by Moncalvo et al. (2002) and an ITS analysis by Babos et al. (2011), bootstrap support is lacking in those analyses.

Sections included

Coccineae and Firmae.

Comments

The basionym of the type species, H. coccinea, has sometimes been confused with Agaricus coccineus Scop. (a diminutive species of Mycena), which is an earlier homonym of a conserved name. In pers. comm. from S. Pennycook (13 Apr 2012), he explained: “In the sanctioning work (p. 105), Fries referred (indirectly) the name to “Pers Obs. Myc. 2. p. 49. Syn. 334. Wulf. In Jacq. Coll. 2. p. 106. [etc.]”. Wulfen is the earliest of the numerous references. However, Wulfen (Misc. Austriac. 2: 106. 1781) explicitly referred the name to Schaeffer, and so did Persoon (Syn. Meth. Fung.: 334. 1801). In the 1821 volume index (p. 508), Fries cited the name as “coccineus Wulf.”; and in Syst. Mycol. Index Alphabeticus (1832, p. 13; also part of the sanctioning works) he cited the sanctioned A. coccineus as “Wulf. Pers.” (along with four unsanctioned A. coccineus homonyms), but in Epicrisis (1838, p. 330) and Hymen. Eur. (1874, pp. 417–418), he made the indirect reference explicit, citing the basionym of Hygrophorus coccineus as Agaricus coccineus Shaeff. [Fung. Bavar. Palat. Nasc. 4: 70. 1774].”

Hygrocybe species in subg. Pseudeudohygrocybe typically differ from those in subg. Hygrocybe in having relatively short lamellar trama hyphae with right-angled septa and long basidia relative to spore length (Fig. 9). Currently, subg. Pseudohygrocybe s.s. has one widely recognized section – Coccineae, while sect. Firmae Heinem. with dimorphic spores and basidia has been recognized by some tropical agaricologists (Cantrell and Lodge 2001, Courtecuisse 1989, Heim 1967, Pegler 1983), but not others (Horak 1971, Singer 1986, Young 2005). Our Hygrocybe LSU analysis (Online Resource 7) strongly recovers a sister relationship with subg. Hygrocybe, albeit without bootstrap support. Though H. miniata is universally regarded as belonging to the same section as H. coccinea (i.e., in sect. Coccineae), our LSU analysis of tribe Hygrocybeae instead places H. miniata in a strongly supported clade that is sister to sect. Firmae s.s. (100 % MLBS). We have retained sect. Firmae and leave the unnamed H. miniata clade unplaced. The remaining former sections of subg. Pseudohygrocybe are treated here as segregate genera. The genus Hygroaster could be reduced to a subgenus or to section rank in subg. Pseudohygrocybe to keep the genus Hygrocybe s.l. monophyletic (i.e., including the segregate genera Hygroaster, Neohygrocybe, Humidicutis, Gliophorus, Porpolomopsis and Chromosera in Hygrocybe). Sect. Coccineae s.s. currently has three subsections: Puniceae, Siccae and Squamulosae. Additional sections and subsections will likely be named in Hygrocybe subg. Pseudohygrocybe with further sampling of gene regions and taxa.

Fig. 9 Hygrocybe (subg. Pseudohygrocybe) sect. Coccineae, Hygrocybe purpureofolia lamellar cross section (NC-64, DJL05NC64). Scale bar = 20 μm Full size image

Hygrocybe sect. Coccineae Fayod, Proc. Hist. Nat. Agar. Ann. Scient. Nat. 7(9): 309 (1889).

Lectotype species: Hygrocybe coccinea (Schaeff.) Fr., Epicr. syst. mycol. (Upsaliae): 330 (1838) [1836–1838], designated by Singer (1951) [1949],

≡ Agaricus coccineus Schaeff. Fung. Bavar. Palat. 4: 70 (1774),

≡ Pseudohygrocybe coccinea (Schaeff.: Fr.) Kovalenko (1988)].

[= Hygrocybe sect. Puniceae Fayod (1889), superfluous, illegit.],

[= Hygrocybe sect. “Inopodes” Singer (1943), nom. invalid].

Characters as in subg. Pseudohygrocybe except basidia and spores always monomorphic.

Phylogenetic support

There are too few species in our 4-gene backbone analyses to draw conclusions regarding subg. Pseudohygrocybe sections. The ITS-LSU analysis shows strong (91 % MLBS) support for a branch connecting subsects. Coccineae and Siccae, while subsect. Squamulosae appears as a separate clade. The grade in our Supermatrix analysis has a branch with low support (44 % MLBS) subtending subsects. Coccineae and Siccae, while subsect. Squamulosae is basal (60 % MLBS). Our Hygrocybe LSU analysis (Online Resource 7) shows sect. Coccineae as a grade with strong support for subsect. Squamulosae (97 % MLBS).

Subsections included

There are currently three validly named subsections in sect. Coccineae, namely Coccineae, Siccae and Squamulosae.

Comments

Both Hygrocybe sects Coccineae and Puniceae were first validly published by Fayod (1889) in the same publication. Singer [(1949) 1951, p. 152] recognized that the type species of these two sections, H. coccinea and H. punicea, belonged in the same section, and between the two competing names he selected Coccineae over Puniceae. Thus sect. Coccineae is the correct name for this group. Previously, Singer (1943) had erected sect. “Inopodes”, nom. invalid, which contained H. punicea (lacking a Latin description, Art. 36.1).

Hygrocybe [subg. Pseudohygrocybe sect. Coccinea ] subsect. Coccineae (Bataille) Singer, Agar. Mod. Tax., Lilloa 22: 152 (1951)[1949].

[= Hygrocybe subsect. Puniceae (Fayod) Arnolds ex Candusso (1997), superfluous, illeg. = Hygrocybe subsect. “Inopodes” Singer (1952), nom. invalid].

Type species: Hygrocybe coccinea (Schaeff.) Fr., Epicr. syst. mycol. (Upsaliae): 330 (1838) [1836–1838]] [≡ Agaricus coccineus Schaeff. Fung. Bavar. Palat. 4: 70 (1774), ≡ Pseudohygrocybe coccinea (Schaeff.: Fr.) Kovalenko (1988)].

Pileus brightly colored, lubricous or viscid at least when young. Lamellae broadly adnate or slightly sinuate, sometimes with a decurrent tooth. Basidiospores usually narrow (mean Q 1.5–2.4), often constricted; mean ratio of basidia to basidiospore length > 5. Pileipellis a persistent or ephemeral ixocutis or mixed ixocutis-ixotrichodermium with narrow hyphae (2–5 μm wide) embedded in gel over hyphae of moderate diameter (6–12 μm wide). Chains of ellipsoid to subglobose hyphal elements generally absent from the hypodermium.

Phylogenetic support

Our ITS-LSU analysis strongly supports subsect. Coccineae as a monophyletic clade comprising H. coccinea and H. punicea (100 % MLBS, Fig. 4). Our Supermatrix strongly supports subsect. Coccineae (H. coccinea, H. punicea and H. purpureofolia) if H. mucronella is excluded (84 % MLBS), but support drops to 46 % MLBS if the H. mucronella complex is included. Our large LSU analysis has 100 % MLBS support for a monophyletic clade comprising the H. coccinea species complex, our LSU analysis of tribe Hygrocybeae has modest support (50 % ML BS) for a clade comprising H. coccinea, H. punicea and H. purpureofolia, and our ITS analysis has only weak support for the subsect. Coccineae clade. Support for including H. ceracea and H. constrictospora in Coccineae is low in the Supermatrix analysis (44 % MLBS), absent in our LSU analysis of tribe Hygrocybeae (Online Resource 7) and absent in ITS analyses (ours and Dentinger et al., unpublished data). Dentinger et al. (unpublished data) shows moderate support (61 % MLBS) for a clade comprising H. coccinea, H. punicea and H. splendidissima.

Species included

Type: Hygrocybe coccinea. Hygrocybe punicea and H. purpureofolia are included in subsect. Coccineae based on molecular and morphological data. H. aurantiosplendens is similar to species in sect. Coccineae, and an ITS analysis by Dentinger et al. (unpublished data) places this species near H. coccinea, so we include it in subsect. Coccineae. There is some molecular support for including H. splendidissima, but we exclude it based on the dry pileus surface, narrowly attached lamellae and broader spores, which are all deviating characters. Hygrocybe ceracea, H. constrictospora, H. insipida, H. miniata, H. mucronella, H. salicis-herbaceae and H. subminutula are tentatively excluded, though the morphology of H. salicis-herbaceae matches the diagnosis of H. subsect. Coccineae.

Comments

In 1943 Singer erected Hygrocybe subsect. “Inopodes”, nom. invalid, then reduced the rank to subsect. in 1951 (1949) and designated H. punicea as the type species. The name is invalid because neither it nor its basionym had a Latin description (Art. 36.1). Thus subsect. Coccineae (Bataille) Singer (1951) is the only validly published subsection name for this group in Hygrocybe. The type of H. subsect. Puniceae (Fayod) Arnolds ex Candusso (1997) falls into this subsection, making it superfluous, thus a nom. illegitimate.

Boertmann (1995, 2010) included H. aurantiosplendens, H. ceracea, H. insipida, H. punicea and H. salicis-herbacea in subsect. Coccineae. Only H. ceracea, H. coccinea and H. punicea are included in our Supermatrix analysis, which provides only weak support for them as comprising the same clade with H. constrictospora, H. purpureofolia, H. subminutula and H. mucronella. All of these species, however, share the diagnostic characters of subsect. Coccineae. Arnolds (1986a), however, placed H. constrictospora in subsect. Squamulosae instead of subsect. Coccineae based on pileipellis structure. Our Supermatrix and ITS analyses (< 50 % ML BS support), and the ITS analysis by Dentinger et al. (7 % MLBS) place H. mucronella near H. ceracea and H. insipida (plus H. quieta and H. salicis-herbacea in Dentinger et al., unpublished). Kovalenko (1989), Arnolds (1990) and Bon (1990) regarded H. insipida as closely related to H. mucronella, but Boertmann thought it was related to H. coccinea and H. ceracea. If all these species belong to the same group, then all are in agreement. Alternatively, H. mucronella, H. ceracea, H. insipida and H. subminutula may be best regarded as unplaced (see Online Resource 8). Although our Supermatrix analysis weakly supports (61 % MLBS) inclusion of H. reidii as basal in the H. ceracea – H. constrictospora clade, H. reidii differs in having a dry pileipellis with a mixture of vertical and horizontal elements, and is the type of subsect. Siccae (see below).

Hygrocybe [subg. Pseudohygrocybe sect. Coccineae ] subsect. Siccae Boertm., The genus Hygrocybe, Fungi of Northern Europe (Greve) 1:15 (1995).

Type species: Hygrocybe reidii Kühner, Bull. trimest. Soc. mycol. Fr. 92: 463 (1976).

Pileus smooth, matt, dry or slightly greasy when young from an ephemeral ixicutis. Stipe dry and smooth. Pileipellis hyphae of intermediate diameter (3–9 μm wide), with interwoven horizontal and vertical elements; ovoid to subglobose elements absent from the hypodermium. Basidiospores constricted and rather narrow, mean Q 1.6–2.1; mean ratio of basidia to basidiospore length >5. Some species have characteristic odors.

Phylogenetic support

Elements of subsect. Siccae are weakly supported in ITS analyses (27 % MLBS for H. reidii and H. constrictospora in our analysis, Online Resource 8, and 34 % MLBS in Dentinger et al., unpublished). These two species appear in the same clade in our Supermatrix analysis (61 % MLBS) but together with H. parvula and H. ceracea. Using ITS analyses, H. quieta appears on a separate branch emerging from the backbone in our analysis, while it appears near H. ceracea and H. mucronella in the analysis by Dentinger et al. (unpublished data). In our ITS-LSU analysis, H. reidii is recovered as sister to H. miniata (Fig. 4). We have tentatively retained sect. Siccae because the type species is not included with strong support in other clades.

Species included

Type species: H. reidii Kühner. There is morphological and some phylogenetic support for including H. constrictospora in this subsection.

Comments

Boertmann (1995) included H. constrictospora, H. quieta, H. splendidissima, H. phaeococcinea, and H. aurantia in subsect. Siccae. The position of H. quieta is unresolved. Candusso (1997, p. 532) and Arnolds (1990) have used Hygrocybe obrussea (Fr.) Wünsche (1877) is an earlier name for Hygrophorus quietus Kühner (1947), but as noted by Bon (1990) and Boertmann (1995, 2010), the diagnosis in Fries (1821) of Agaricus obrusseus is too vague to be sure of what species was intended, and therefore a nomem dubium. As it is not the intent of this paper to resolve such issues when they do not involve type species of genera or infrageneric taxa, we have used the name H. quieta as we are certain that our DNA sequences represent that species. While H. phaeococcinea fits subsect. Siccae morphologically, it is allied with H. miniata in ITS analyses by us and Dentinger et al. (unpublished). ITS analyses (ours and Dentinger et al., unpublished data) place H. splendidissima as sister to H. punicea with strong support, but the morphological characters fit subsect. Siccae and not Coccineae. Our molecular phylogenies show H. aurantia belongs in Cuphophyllus.

Hygrocybe [subg. Pseudohygrocybe sect. Coccineae ] subsect. Squamulosae (Bataille) Singer, Lilloa 22: 152 (1951) [1949]

[≡ Hygrocybe subsect. Turundae (Herink) Bon, Doc. Mycol. 19(75): 56 (1989), superfluous, nom. illeg.].

Type species: Hygrocybe turunda (Fr.) P. Karst., Bidr. Känn. Finl. Nat. Folk 32: 235 (1879)

≡ Hygrophorus turundus (Fr.: Fr.) Fr., Epicr. syst. mycol. (Upsaliae): 330 (1838),

≡ Agaricus turundus Fr., Observationes mycologicae 2: 199 (1818).

Pileus subglobose at first, depressed in center, often deeply depressed or infundibuliform at maturity; surface dry, squamulose or minutely tomentose; stipe dry and smooth. Lamellae often arcuate-decurrent. Pileipellis a trichoderm at the center, of broad hyphae (6–8–25 μm wide), typically with subglobose to ovoid elements in the hypoderm. Basidiospores relatively broad, Q 1.2–1.7 (−1.8); mean ratio of basidia to basidiospore length >5, constricted or not.

Phylogenetic support

The core of subsect. Squamulosae is strongly supported as a monophyletic clade in our Supermatrix, full LSU, Hygrocybe LSU and ITS analyses (100 %, 99 %, 97 % and 84 % MLBS, respectively). The Squamulosae clade in our Supermatrix analysis comprises H. caespitosa, H. cantharellus and H. melleofusca. Support for this branch falls below 50 % in our ITS-LSU ML analysis. Babos et al. (2011), show 98 % BS support for the clade comprising H. turundus and H. lepida (as H. cantharellus; see Arnolds 1986b), while Dentinger et al. (unpublished data) show 100 % MLBS support for the clade comprising H. cantharellus s.s., H. lepida (as H. cantharellus), H. caespitosa, H. coccineocrenata, H. melleofusca and H. turunda using ITS alone. The ITS analsysis by Babos et al. (2011) shows moderately high support for including H. quieta in this clade (74 %), but the analysis by Dentinger et al. (unpublished) does not support inclusion of H. quieta in subsect. Squamulosae. In our ITS analysis, the subsect. Squamulosae clade comprises H. caespitosa, H. cantharellus, H. lepida, H. melleofusca, H. papillata and H. turunda with 84 % MLBS support, but H. quieta appears on a long branch in a separate clade. Although H. miniata is traditionally treated in subsect. Squamulosae, which is consistent with the micromorphology and an ITS analysis by Babos et al. (2011) that places H. miniata in a sister clade to subsect. Squamulosae s.s. (78 % MLBS). Our ITS analysis (Online Resource 8) places the clade containing H. miniata and H. phaeococcinea near sect. Firmae, and the ITS analysis by Dentinger et al. shows strong support (93 % MLBS) for sect. Firmae as sister to the H. miniata—H. phaeococcinea clade, but not near subsect. Squamulosae.

Species included

Type species: Hygrocybe turunda (Fr.) P. Karst. Hygrocybe cantharellus (Schwein.) P. Karst. H. caespitosa Murrill, H. coccineocrenata (P.D. Orton) M.M. Moser, H. lepida Arnolds, H. melleofusca Lodge & Pegler (if different from H. caespitosa), H. substrangulata (Peck) P.D. Orton & Watling, and H. turunda (Fr.) P. Karst. are included based on molecular and morphological data. Although the H. miniata complex has similar morphology, we tentatively exclude it from subsect. Squamulosae because it appears in a clade with sect. Firmae (H. firma, H. martinicensis), H. andersonii, and H. phaeococcinea in our ITS analysis, and as a strongly supported sister to sect. Firmae in our LSU analysis and the ITS analysis by Dentinger et al. (unpublished data).

Comments

Singer [1949 (1951)] inadvertently combined Bataille’s Hygrophorus [unranked] Squamulosi at subsection rank in the genus Hygrocybe. Konrad and Maublanc (1953) combined Bataille’s Squamulosae at higher (section) rank (neither with a designated type species) and Herink published a different name, Turundae, for this group in the genus Hygrocybe with the same type (H. turundua) as Singer’s subsection and he included a Latin diagnosis; Herink included H. cantharellus and an ambiguous species, H. marchii sensu Karsten. Excluding H. marchii, Herink’s section refers to the same clade as Hygrocybe subsect. Squamulosae. Bon (1989) reduced Turundae to subsect. rank and included only the type species, which is characterized by having a pileus with darkening squamules. Hygrocybe turunda is in subsect. Squamulosae Singer (1951), making subsect. Turundae (Herink) Bon (1989) superfluous (nom. illeg.). If this clade is recognized at section rank, the correct name is Hygrocybe sect. Squamulosae (Bataille) Konrad and Maubl. (1953) based on priority.

Our Supermatrix and ITS analyses strongly support inclusion of H. caespitosa, H. coccineocrenata, H. lepida, H. melleofusca, H. substrangulata, and H. turunda in subsect. Squamulosae. Lodge and Pegler (1990) and Cantrell and Lodge (2004) incorrectly placed H. melleofusca in Hygrocybe sect. Neohygrocybe based on the brown staining reactions while Arnolds (1995) had correctly placed its sister species, H. caespitosa, in subsect. Squamulosae based on micromorphology of the pileus trama and pellis. Although Singer [(1949) 1951)], Bon (1990) and Boertmann (1995, 2010) all treated H. miniata in subsect. Squamulosae, and we have not found characters that would separate them, phylogenetic support for retaining H. miniata in subsect. Squamulosae is lacking so we have tentatively excluded it along with other species in that clade.

Hygrocybe [subg. Pseudohygrocybe] sect. Firmae Heinem., Bull. Jard. bot. État Brux. 33: 441 (1963).

Type species: Hygrocybe firma (Berk. & Broome) Singer, Sydowia 11: 355 (1958)

≡ Hygrophorus firmus Berk. & Broome, J. Linn. Soc., Bot. 11: 563 (1871).

Emended here by Lodge to exclude species with macrobasidia broader than the microbasidia and basidia less than 5 times the length of their basidiospores.

Characters as in Hygrocybe, sect. Coccineae, subsect. Squamulosae but differing in presence of dimorphic basidiospores and basidia. Shares dimorphic basidia and spores with Hygrocybe, subg. Hygrocybe, sect. Pseudofirmae but differs in having basidia exceeding 5 times the length of their basidiospores, narrow macrobasidia that differ from the microbasidia primarily in length (not width), presence of chains of subglobose elements in the pileus hypoderm, often a trichodermial pileipellis rather than an interrupted cutis, and long lamellar trama hyphal elements always absent.

Phylogenetic support

Sect. Firmae appears in a separate, strongly supported clade in our Hygrocybe LSU analyses (85 % MLBS, Online Resource 7), and ITS analyses of Dentinger et al. (82 % MLBS, unpublished data), but it appears as a grade in our ITS analysis (Online Resource 8). Our LSU (100 % MLBS, Online Resource 7) and Dentinger et al.’s ITS (93 % MLBS) analyses strongly support placing sect. Firmae as sister to the H. miniata clade, and we show only weak ITS support (47 % ML BS) for including the type of sect. Firmae in the H. miniata clade. The sect. Firmae – H. miniata clade is weakly (39 % MLBS) supported as sister to subsect. Squamulosae in our LSU analysis of tribe Hygrocybeae (Online Resource 7), (but these clades are apart in our ITS-LSU analysis. The ITS analysis by Dentinger et al. (unpublished data) does not place sect. Firmae near subsect. Squamulosae.

Species included

Type species: Hygrocybe firma. Hygrocybe martinicensis Pegler & Fiard is included based on phylogenetic and morphological data. Based on morphology of the pileipellis and mean ratios of basidia to basidiospore lengths, H. anisa (Berk. & Broome) Pegler and possibly H. batistae Singer are tentatively included.

Comments

Sect. Firmae was delineated by Heinemann (1963) based on presence of dimorphic basidiospores and basidia, and has been recognized by some tropical agaricologists (Cantrell and Lodge 2001, Courtecuisse 1989, Heim 1967; Pegler 1983), but not others (Horak 1971, Singer 1986, Young 2005). It is now apparent based on our phylogenetic analyses that dimorphic basidiospores and basidia arose several times, appearing in two clades of subg. Hygrocybe (sects. Pseudohygrocybe and Velosae) and one strongly supported monophyletic clade (sect. Firmae ss, Dentinger et al., unpublished data) in subg. Pseudohygrocybe. Species in sect. Firmae can be differentiated from those with dimorphic spores and basidia in subg. Hygrocybe based on the micromorphological features noted in the emended diagnosis above. Species in sect. Firmae have narrow macrobasidia, broad hyphae in the pileipellis and globose mixed with stipitate-capitate elements in the hypodermium, similar to the globose to subglobose elements in the hypoderm of H. cantharellus and related species in subsect. Squamulosae (Fig. 10). Other than the presence of dimorphic basidiospores and basidia, sect. Firmae micromorphologically resembles species in subsect. Squamulosae, where Singer (1986) placed it, and the H. miniata species complex, which Singer and others also placed in subsect. Squamulosae. Despite the micromorphological similarities, phylogenetic analyses by us and by Dentinger et al. (unpublished data) suggest a strong relationship between sect. Firmae and the H. miniata complex, but a weak or absent relationship between that combined clade and subsect. Squamulosae. Additional analyses including more species and gene regions will be needed to resolve relationships among these clades. In keeping with making minimal changes in classification unless strongly justified by phylogenetic analyses, we have retained sect. Firmae and left the H. miniata clade unplaced.

Fig. 10 Hygrocybe (subg. Pseudohygrocybe) sect. Firmae. Hygrocybe firma (type): a. pileipellis; b. hymenium showing macro- and microbasidia; c. microspores; d. macrospores. Scale bar = 20 μm Full size image

Species unplaced subgen. Pseudohygrocybe.

Hygrocybe miniata, H. miniata f. longipes, and H. phaeococcinea appear in a well supported clade that is sister to sect. Firmae in our ITS analysis of Hygrocybe s.s. Similarly, the H. miniata species complex falls in a strongly supported (85 % MLBS) sister clade to sect. Firmae (H. firma s.s. and H. martinicensis) in our LSU analysis of tribe Hygrocybeae (Online Resource 7). Hygrocybe miniata shares with subsect. Squamulosae large diameter pileipellis hyphae (5–18 μm), presence of subglobose elements in the pileus hypoderm and small mean spore Q (1.3–1.6). Consequently, Singer [(1949) 1951), Bon (1990) and Boertmann (1995, 2010)] all treated H. miniata in subsect. Squamulosae. The H. miniata – sect. Firmae clade (100 % MLBS) appears as sister to subsect. Squamulosae (97 % MLBS) with low support (39 % MLBS) in our LSU analysis of tribe Hygrocybeae while the H. miniata complex and sect. Squamulosae appeared in sister clades with strong support (77 % MLBS) in the ITS analysis by Babos et al. (2011). In our Supermatrix analysis, H. miniata f. longipes is included in the basal clade of subgen. Hygrocybe with H. helobia, but without significant bootstrap support (32 % ML); the short lamellar trama hyphae in H. miniata argues against that placement. Inclusion of H. firma, the type of sect. Firmae, as sister to the H. miniata clade, and these together as sister to sect. Coccineae subsect. Squamulosae is problematical on several levels. Species in sect. Firmae have dimorphic spores and basidia, but otherwise they have all the diagnostic characters of subsect. Squamulosae and species in the H. miniata clade. Singer (1986), Horak (1990) and Young (2005) treated Hygrocybe with dimorphic basidia as members of subg. Pseudohygrocybe, and the phylogenetic placement and micromorphology of the basidiomes of H. firma are concordant with that placement. Singer (1986) frequently included dimorphic basidiospores and basidia in his description of Hygrocybe sect. Coccineae, subsect. Squamulosae, but the phylogenetic analyses presented here and the analysis by Dentinger et al. (unpublished) place the sect. Firmae – H. miniata clade either weakly together with or apart from subsect. Squamulosae. Placing the H. miniata complex as a new subsection of sect. Firmae is one possible solution, but it would neccesitate emending the description of sect. Firmae to include species with monomorphic basidia and spores. There is currently no valid name for a subsection typified by H. miniata. Recognizing the H. miniata clade at section rank is another option, but sect. Miniatae Singer (1943) was not validly published (Art. 36.1). Raising subsect. Squamulosae to section rank also needs to be considered. We have refrained from making such changes, leaving the H. miniata clade unplaced, and sect. Firmae and sect. Coccineae, subsect. Squamulosae at their present ranks.

Hygrocybe calciphila has all the characters of sect. Coccineae subsect. Squamulosae, but its position is unstable between ITS and paired ITS-LSU analyses. In our ITS-LSU analysis and Dentinger et al.’s (unpublished) ITS analysis, H. calciphila falls between subg. Hygrocybe and Pseudohygrocybe without support.

Hygroaster Singer, Sydowia 9(1–6): 370 (1955).

Type species: Hygroaster nodulisporus (Dennis) Singer, Sydowia 9(1–6): 370 (1955)

≡ Hygrophorus nodulisporus Dennis, Kew Bull. 8(2): 259 (1953).

Emended here by Lodge to exclude temperate species, basidiomes with bright pigments and basidiospores that are subangular or are not globose or subglobose.

Pileus indented, not viscid, fuscous or white, lacking bright pigments. Lamellae thick, decurrent, distant or subdistant. Basidiospores subglobose or globose, not polygonal in outline; spines long conical with blunt or acute apices, hyaline, inamyloid, not cyanophilous; ratio of basidia to basidiospore lengths (excluding ornaments) > 5; lamellar trama subregular, hyphal elements short, central strand pigmented in pigmented species; clamp connections usually absent throughout the basidiomes; pigments mostly vacuolar, but pileipellis hyphae may be lightly encrusted; habit terrestrial in wet tropical forests, so far confined to the neotropics. Differing from Omphaliaster in lacking heavily encrusting pigments, if pigmented, absence of pseudocystidia in the hymenium, subregular rather than regular lamellar trama, absence of clamp connections, growing on mineral soil or humus rather than with mosses on small shrubs and rotting wood, and tropical rather than primarily temperate-boreal in distribution.

Phylogenetic support

Support for a monophyletic clade represented by H. nodulisporus and H. albellus is strong in the 4-gene backbone analysis (98 % MLBS and 100 % BPP), LSU analysis (92 %), and Supermatrix (75 % MLBS). Support for Hygroaster as sister to Hygrocybe is strong (98 %, and 96 %, MLBS in our 4-gene backbone and Supermatrix, analyses, respectively).

Species included

Type species: H. nodulisporus. Placement of H. albellus Singer in Hygroaster is confirmed by molecular phylogeny. It is ambiguous as to whether H. cleefii Franco-Molano & López-Quintero belongs in Hygroaster as the presence of clamp connections, broadly ellipsoid rather than globose spore shape and viscid pileus are deviating characters.

Comments

Hygroaster was originally described as a monotypic genus by Singer (1955) to accommodate Hygrophorus nodulisporus Dennis (1953) from Trinidad. Singer then added H. albellus in 1989. While both of Singer’s species lack the bright pigments that are typically found in Hygrocybe s.s., the morphology of the lamellar trama and subhymenium are typical of Hygrocybe (Fig. 11), and the molecular phylogenies strongly support it as the sister clade to Hygrocybe. It is unknown if the dark pigment in H. nodulisporus is a betalain, as in Hygrocybe. If the segregate genera (e.g., Gliophorus, Humidicutis, Neohygrocybe and Porpolomopsis) are treated as sections within the genus Hygrocybe, Hygroaster would need to be reduced in rank to keep Hygrocybe from being polyphyletic. Hesler and Smith (1963) reduced the rank of Hygroaster to a section, but in the genus Hygrophorus rather than Hygrocybe. Treatment of nodulose-spored species of Hygroaster among the smooth spored Hygrocybe is not unreasonable. Several species of Hygrocybe have variants that produce spores with conical spines, such as H. anomala, H. insipida and H. kula (Boertmann 1995; Young 2005). It is therefore likely that the presence or absence of spines on spores in Tribe Hygrocybeae results from mutation or repression/derepression a single gene. It is unkown if the fuscous pigment in H. nodulisporus is a DOPA betalaine, as in Hygrocybe, or another type (Online Resource 4).

Fig. 11 Hygroaster nodulisporus lamellar cross section (PR-6378, Puerto Rico). Scale bar = 20 μm Full size image

In the original description by Singer, the lamellar trama of the type species, H. nodulisporus, was bilateral with a central slightly interwoven strand and divergent hyphae in a gelatinous matrix in the lateral strands. Neither we nor Hesler and Smith (1963) found evidence of gelatinization or bilateral structure in the type, and we have not seen these characters in subsequent collections of H. nodulisporus (Fig. 11), though the central part of the trama is darkly pigmented. In 1986, Singer changed the diagnosis of the trama to subbilateral with pigmented central strand in pigmented species.

Singer’s (1986) tribe Hygroastreae comprises Hygroaster and Omphaliaster, but is polyphyletic, as is Ludwig’s (1997) concept of Hygroaster in which he combined species of Omphaliaster in the genus Hygroaster. As noted by Franco-Molano and López-Quintero, most of the species placed in Hygroaster belong elsewhere. The European species described in Hygroaster by Horak (1966, H. kyrtosporus and H. nauseodulcis) were transferred by Noordeloos (1983) to Omphaliaster (between Tricholomataceae tribe Lyophylleae and the Tricholomatoid clade in Moncalvo et al. 2002; in the Tricholomatoid clade in Matheny et al. 2006). Kühner (pers. com. to EH) suggested that H. kyrtosporus did not belong with H. asterosporus and H. borealis (both now in Omphaliaster). The caulocystidia and the small, smooth ovoid spores attached to basidia in H. kyrtosporus are consistant with Omphalina spp., while the very large nodulose spores might be chlamedospores of a parasite as they closely resemble those of Nyctalis parasitica. Singer (1962) [1961] transferred Omphalia asterospora into Hygroaster, but Lamoure (1971) transferred it to Omphaliaster. The transfer of Rhodocybe ianthinocystis into Hygroaster by Ludwig (1997) is rejected in favor of placement by Baroni (1981) in Omphaliaster based on the presence of pseudocystidia in the hymenium, parallel lamellar trama hyphae and lower ratio of basidia to basidiospore lengths (4–4.5 according to Baroni, but up to 5.2 according to Singer, versus 5.5–7 in Hygroaster). Singer (1986) suggested an alternative placement of this species in Asproinocybe. While Hygroaster lacteus E. Ludw. and Ryberg (Ludwig 1997) described from Europe has nodulose spores, it deviates from Hygroaster s.s. in having prominent pseudocystidia and clamp connections. The nodulose spore ornamentation in H. lacteus is unlike the ornaments on Omphaliaster spores, and DNA sequencing will likely be needed to resolve its affinities. Placement of several tropical species assigned to Hygroaster is also complex. The South American H. iguazuensis Lechner & J.E. Wright is bright orange and has spores that are more elongated and polygonal in outline, resembling nodulose-spored forms in Hygrocybe anomala, and it likely belongs in Hygrocybe s.s. (Franco-Molano and López-Quintero 2007). It is uncertain where the Asian H. sulcatus (Z.S. Bi) T.H. Li & Z.S. Bi and H. trachysporus Bi belong, but presence of pleurocystidia in the former, a glutinous pileus in the latter, and presence of bright pigments, clamp connections and small Lepista-like ornamentation on broadly ellipsoid spores in both species argue against placement in Hygroaster. Hygroaster fucatus Vrinda & Pradeep. described from India (Vrinda et al. 2012) deviates from Hygroaster in having orange pigments in the pileus, lamellae that are adnexed rather than decurrent and tinted lilac, ellipsoid spores with inocyboid ornamentation, and presence of clamp connections and pleuro- and cheilocystidia; H. fucatus is likely conspecific with or close to Asprinoinocybe russuloides that was described from Africa. The data on H. agumbensis Sathe & S.M. Kulk from India are insufficient to place this species.

Tribe Humidicuteae Padamsee & Lodge, tribe nov.

MycoBank MB804050.

Type genus: Humidicutis (Singer) Singer, Sydowia 12(1–6): 225 (1959) [1958].

Basidiomes brightly colored or gray brown, differing from Hygrocybe in absence of DOPA based pigments except for in a few species of Neohygrocybe. Clamp connections at the base of basidia and basidioles often toruloid and then differing from those in Chromosera. Also differing from Chromosera in having regular or subregular but not interwoven lamellar context, inamyloid pileus context, and strong odors in some species.

Phylogenetic support

The tribe comprising Neohygrocybe, Gliophorus, Humidicutis, and Porpolomopsis consistently appears either as a single clade that is sister to Hygroaster (with Hygroaster basal to Hygrocybe) (4-gene backbone and LSU analyses) or in adjacent clades (ITS-LSU and Supermatrix analyses). Support for a monophyletic tribe Humidicutae comprising all four genera is 89 % MLBS in the 4-gene backbone analysis (99 % MLBS for it being a sister to tribes Hygrocybeae and Chromosereae), but support falls below 50 % in our LSU analysis. In the ITS-LSU analysis, Neohygrocybe appears as sister to the Humidicutis – Porpolomopsis clade. These four genera are usually basal to Hygroaster—Hygrocybe s.s. (tribe Hygrocybeae) and distal to Hygrophorus and other genera of Hygrophoraceae. Based on the strongly supported placement of Hygroaster—Hygrocybe s.s. as sister to the Gliophorus – Humidicutis – Neohygrocybe – Porpolomopsis clade, it is untenable to treat these groups as sections within subg. Pseudohygrocybe, where the first three have traditionally been placed. Prior to Horak (1990), Young (2005) and Boertmann (2010), who placed Porpolomopsis species in Humidicutis, Porpolomopsis was treated in subg. Hygrocybe because it has long, tapered lamellar trama hyphae – an untenable placement that would render subg. Hygrocybe polyphyletic.

Genera included

Comprising the type genus, Humidicutis, together with Gliophorus, Gloioxanthomyces, Neohygrocybe and Porpolomopsis.

Comments

These segregate genera are often treated at subgenus or section rank within the genus Hygrocybe (Table 1), which is justifiable as long as the genus Hygroaster is reduced to a subgenus so it doesn’t render Hygrocybe polyphyletic. We have selected subgeneric over section ranks for recommended names when using Hygrocybe s.l. (Table 1) because they are strongly divergent, and there are more validly published names available when they are treated at this rank.

Neohygrocybe Herink, Sb., Severocesk. Mus., Prír. Vedy 1: 71 (1959).

Type species: Neohygrocbye ovina (Bull. : Fr.) Herink, Sb. Severocesk. Mus., Prír. Vedy 1: 72 (1959)

≡ Hygrophorus ovinus (Bull. : Fr.) Fr., Epicr. syst. mycol. (Upsaliae): 328 (1838) [1836–1838],

≡ Agaricus ovinus Bull., Herbier de la France 13: 592 and plate 580 (1793)] Lectotype here designated as fig. M in Bulliard, Herbier de la France 13: plate 580 (1793)]; Epitype here designated GEDC0877, coll. Griffith, Ffriddoedd Garndolbenmaen, Wales, UK, 19 Oct 2006, K(M)187568, GenBank sequences KF291228, KF291229, KF291230.

Pileus hemispherical or campanulate, center usually umbonate and margin incurved when young, often plane or convex or with depressed center and margin lobed with age; surface dry or moist, minutely tomentose, appressed squamulose or fibrillose, often rimose; pigments grayish brown, mostly with oxidation reactions that produce red, then fuscous colors upon bruising, DOPA pigments present or absent; lamellae adnexed sinuate or broadly adnate, thick, waxy, distant and fragile; stipe central, often compressed or channeled, surface smooth, context stuffed or hollow; flesh usually with distinct odors (nitrous, chlorine or fruity); basidiospores hyaline, thin-walled, ellipsoid, oblong or broadly ellipsoid, rarely broadly ovoid or subglobose, not strangulated, guttulate in KOH, guttules with oily contents, inamyloid; basidia 2- or 4-sterigmate, with modest basal clamp connections; basidia more than 5 times the length of the spores; lamellar trama subregular or regular, hyphae up to 200–400 μm in length, with clamp connections; pseudocystidia absent or present, emanating from the context and protruding from the lamellar edge or sides, sometimes with dissolved fuscous pigment; pileipellis a loose cutis, disrupted cutis or trichoderm, often with dissolved fuscous pigment. Differs from Humidicutis, Porpolomopsis and most Gliophorus species in lacking bright pigments and clamp connections at the base of the basidia and basidioles not toruloid; differs from Gliophorus in absence of glutinous surfaces; differs from Porpolomopsis in having subregular rather than regular lamellar trama, and fuscous rather than purple pigments.

Phylogenetic support

Support for a monophyletic Neohygrocybe is strong in our 4-gene backbone, Supermatrix and ITS-LSU analyses (99 %, 87 % and 76 %, respectively), and moderate in our ITS analysis (Online Resource 3, 61 % MLBS); N. nitrata was dropped from these analyses, however, because it caused instability. Support is moderate (67 % MLBS) in our LSU analysis, excluding N. nitrata from Turlogh Hill in North Wales, UK but including N. aff. nitrata from Russia (there is no significant backbone support separating the two representatives identified as N. nitrata). The ITS analysis of subf. Humidicutae by Dentinger et al. (unpublished) places N. nitrata apart from the other Neohygrocybe species along the backbone.

Sections included

Neohygrocybe and Tristes.

Comments

The genus Neohygrocybe was described by Herink (1959) to accommodate the gray-brown species formerly treated in Hygrocybe that lacked viscid surfaces, had strong odors and usually had tissues that bruised red and then fuscous. It has previously been accepted at genus rank by Kovalenko (1989), or treated within the genus Hygrocybe at the rank of either subgenus (Bon, 1990) or section (Boertmann 2010; Candusso 1997; Cantrell and Lodge 2004; Lodge and Pegler 1990, Pegler and Fiard 1978). Bon (1989) validly combined it in Hygrocybe as subg. Neohygrocybe (Herink) Bon (citing the basionym and source publication, and indirectly inferring the type species, H. ovina, was the same as the type of Neohygrocybe, as allowed in Art. 37.3). We recognize two sections in Neohygrocybe: sects. Neohygrocybe (the correct name for sect. “Ovinae” Herink, nom. invalid, Art. 22.1), and sect. Tristes (Bataille) Singer, which replaces the superfluous sect. Nitratae Herink (illeg., Art. 52.1). We have emended the diagnosis of sect. Tristes to match the narrower limits of Herink’ sect. Nitratae rather than Singer’s broader sect Tristes.

Herink (1959) made an attempt to erect a provisional section, “Metapodiae”nom. invalid, in Neohygrocybe for a fuscous, red-staining species with smooth, amyloid spores, Porpoloma metapodium. Singer (1986) later placed Porpoloma in the Tricholomataceae, Tribe Leucopaxilleae – a placement supported by molecular phylogenetic analysis of LSU sequences (Moncalvo et al. 2002) (see excluded genera).

Herink designated N. ovina as type of Neohygrocybe, mentioning both Bulliard and Fries. Thus the type of the generic name is N. ovina (Bull. : Fr.) Herink (basionym Agaricus ovinus Bull. : Fr.) and it is the type of this species epithet that is the type of the genus. The nomenclatural history of Agaricus ovinus Bull. : Fr. is complex. Fries (1821) placed Agaricus metapodius Fr. (1818) in synonymy with A. ovinus Bull. : Fr., and the figures in Bulliard’s plate 580 (Herb. Fr., 1793) that Fries cited (excluding figs. a and b = Dermoloma) indeed represent a mixture of A. ovinus and A. metapodium (the latter species now in Porpoloma, Tricholomataceae), though Fries later clearly distinguished these two species (1838: 328). Agaricus ovinus Bull.: Fr., however, is a sanctioned name (Systema Mycol. 1: 109, 1821) and is thus protected against competing synonyms and homonyms (including A. metapodium); moreover, H. ovinus (1793/1801) has priority over A. metapodius (1818), regardless of protected status (S. Pennycook, pers. comm. 27 June 2013). Thus the use of ‘type Hygrocybe ingrata’ by Candusso (1997: 323) and recognition by Della Maggiora and Matteucci (2010) of H. nitiosa (A. Blytt) M.M. Moser (1967), with Hygrocybe ovina (Bull.: Fr.) Kühner ss Kühner (1926) as a facultative synonym, and exclusion of Agaricus ovinus Bull. is problematic on many levels. As Fries did not designate a type, the material cited by Fries represents a mixture of species (and collections) and we have not found a subsequent lectotype designation for A. ovinus Bull. : Fr., we have instead chosen to stabilize its concept according to Art. 9.2, 9.10, and 9.11 by designating figure M in Bulliard plate 580 (Herb. Fr., 1793) as the lectotype of Agaricus ovinus Bull. : Fr., and by designating a photo documented and sequenced collection from Wales (GEDC0877, K(M)187568) as an epitype. The designated lectotype and epitype closely resemble each other and conform to the original diagnosis (both have an innately scaly pileus with split margins, a compressed stipe which indicates they are stuffed or hollow, and a slight flush of pink in the gray lamellae (but neither shows a distinct red staining, which is a character not included in the original diagnosis). The absence of characters from the diagnosis (e.g., pink staining reaction and nitrous odor, as noted by Candusso, 1997) are ignored as it is the characters that are present in a diagnosis that must match the selected lectotype and epitype. We have instead selected the lectotype and epitype based on the following characters that were included in the original diagnosis (Bull., Herb. Fr., 1793: 592) of A. ovinus Bull.: stipe swollen, stuffed, becoming hollow; pileus 2–6 cm diam., hemispherical, becoming umbonate, smooth to scaly, margin becoming fissured, brick colored to fuscous-cinereous; lamellae few, sublunate, uncinate, broad, venose, white at first, becoming cinerous. Porpoloma metapodium has a solid, non-compressed stipe and lamellae that are not veined.

Neohygrocybe sect. Neohygrocybe. [autonym]

[≡ Neohygrocybe sect. “Ovinae” Herink (1959), nom. invalid and illeg.]

Type species: Neohygrocybe ovina (Bull.: Fr.) Herink, Sb. Severocesk. Mus., Prír. Vedy 1: 72 (1959)

[≡ Hygrocybe ovina (Bull.: Fr.) Kühner, Le Botaniste 17: 43 (1926), ≡ Hygrophorus ovinus (Bull. : Fr.) Fr., Epicr. syst. mycol. (Upsaliae): 328 (1838) [1836–1838],

≡ Agaricus ovinus Bull., Herbier de la France 13: t. 580 (1793)].

Characters as in genus Neohygrocybe, some part of the flesh always bruising red, then fuscous; most with a distinctive nitrous, ammonia or fruity odor.

Phylogenetic support

Support for a monophyletic sect. Neohygrocybe is strong in our 4-gene backbone, LSU, Supermatrix and ITS-LSU analyses (99 %, 67 %, 87 % and 76 % MLBS, respectively). Support is moderate in our ITS analysis (61 %, Online Resource 3).

Species included

Type species: Neohygrocybe ovina. Additional species included based on molecular phylogenies and morphology are N. ingrata and N. subovina (Hesl. & A.H. Sm.) Lodge & Padamsee, comb. nov. (below). Neohygrocybe lawsonensis (A.M. Young) Lodge & Padamsee, comb. nov. (below) is included based on morphology.

Comments

This section contains most of the species known in Neohygrocybe including the type, but it has previously been called Neohygrocybe sect. “Ovinae” Herink (nom. invalid), and Hygrocybe [unranked] Ovinae Bataille. Herink (1959) supplied a Latin diagnosis for the unranked group, Ovini Bataille (1910), but Herink failed to cite the basionym and its place of publication as required beginning in 1953 (nom. invalid, Art. 33.4). Regardless, sect. Ovinae is invalid because the section contains the type of the genus so the name has to repeat the genus name exactly (Art. 22.1), making sect. Neohygrocybe the correct name for this group. The combinations in Hygrocybe, sect. Neohygrocybe (Herink) Bon, and immediately below it, N. subsect. Neohygrocybe (Herink) Bon (1989), were both validly published making Hygrocybe sect. Neohygrocybe (Herink) Candusso (1997) superfluous, nom. illeg. (Candusso, 1997: 323, was also incorrect in stating the type species of the section was H. ingrata; see Art. 7.4).

Neohygrocybe subovina (Hesl. & A. H. Sm.) Lodge & Padamsee, comb. nov.

MycoBank MB804063.

Basionym: Hygrophorus subovinus Hesler & A. H. Sm., North American species of Hygrophorus: 162 (1963).

Type: TENNESSEE, Cade’s Cove, Great Smoky Mt. National Park, 8 Jun 1957, on soil in deciduous woods, Hesler 22583, TENN.

Neohygrocybe lawsonensis (A. M. Young) Lodge & Padamsee, comb. nov.

MycoBank MB804064.

Basionym: Hygrocybe lawsonensis A. M. Young in A. M. Young & A. E. Wood, Austral. Syst. Bot. 10(6):981 (1997).

Type: AUSTRALIA, New South Wales, on soil in sclerophyll forest, T. Lawson, 30 May 1992, UNSW 92/211.

Neohygrocybe sect. Tristes (Bataille) Lodge & Padamsee, comb. nov.

MycoBank MB804067.

Basionym: Hygrophorus [unranked] Tristes Bataille, Mém. Soc. émul. Doubs, sér. 8 4:183 (1910).

≡ Hygrocybe sect. Tristes (Bataille) Singer, Lilloa 22: 151 (1951) [1949]

[≡ Neohygrocybe sect. “Nitratae” Herink, superfluous, nom. illeg., Art. 52.1],

Lectoype designated by Singer (1951): Hygrocybe nitrata (Pers.) Wünsche, Die Pilze: 112 (1877),

≡ Agaricus nitratus Pers., Syn. meth. fung. (Göttingen) 2: 356 (1801),

≡ Neohygrocybe nitrata (Pers.) Kovalenko, Opredelitel’ Gribov SSSR (Leningrad): 40 (1989),

[≡ “Neohygrocybe nitrata” (Pers.) Herink (1959), nom. invalid., Art. 33.2].

N. Sect. Tristes is emended here by Lodge to include only the type species.

Odor nitrous. Differs from sect. Neohygrocybe in flesh not staining red when bruised.

Phylogenetic support

The collection sequenced from North Wales (as H. nitrata) matches the type description, so we assume that the collection sequenced from Russia is an un-named cryptic species in sect. Nitratae. The collection identified as N. nitrata from N.Y. in the Supermatrix analysis is apparently N. ingrata. Inclusion of species of sect. Nitratae in phylogenetic analyses caused instability, but we retained them in the LSU analysis. N. nitrata and N. aff. nitrata appeared in separate clades in the LSU analysis. The LSU sequence from the Russian collection appears on a long branch near the base of sect. Neohygrocybe while the sequence from the Welsh Turlogh Hill collection appears on a long branch from the backbone. The ambiguous support for this group indicates a need for further revision with greater taxon sampling, so we have tentatively retained the section.

Species included

Type species: Neohygrocybe nitrata. An un-named taxon from Russia resembling N. nitrata likely also belongs here based on morophology and molecular sequences.

Comments

Sect. Tristes (Bataille) Singer (1951) replaces the superfluous sect. Nitratae Herink (1959) based on priority, but we retained Herink’s narrower circumscription for this group. Some collections of N. nitrata reportedly have faint staining reactions, (DMB) and the placement of these needs to be verified with DNA sequencing.

Porpolomopsis Bresinsky, Regensb. Mykol. Schr. 15: 145 (2008).

Type species: Porpolomopsis calyptriformis (Berk.) Bresinsky, Regensb. Mykol. Schr. 15: 145 (2008)

≡ Hygrocybe calyptriformis (Berk.) Fayod, Annls. Sci. Nat. Bot., sér. 7 9: 309 (1889),

≡ Agaricus calyptriformis Berk., Ann. Mag. Nat. Hist., Ser. 1 1: 198 (1838).

Pileus conic, conico-campanulate, convex-umbonate or cuspidate, frequently splitting through the pileus and lamellar context near the pileus margin; pigments nonencrusting and insoluble in alkali, salmon, pink, lilac, vinaceous or absent (white); lamellae narrowly attached (adnexed, narrowly sinuate) or free; pileipellis hyphae radially arranged, fusiform; basidia usually 5 or more times longer than the spore length; basidiospores hyaline, thin-walled, inamyloid, not metachromatic, ellipsoid or broadly ellipsoid, not stangulated; lamellar trama strictly regular, of long, fusiform hyphae often exceeding 140 μm in length, with right-angled septa; clamp connections typically absent or rare in context and the pellis, but toruloid clamps present at base of basidia and/or basidioles. Differing from Humidicutis in narrowly attached or free lamellae, splitting of the context through the pileus and lamellae, and long, parallel, fusiform trama hyphae.

Phylogenetic support

Support for a monophyletic Porpolomopsis is strong in our ITS-LSU, ITS and 4-gene backbone analyses (100 % MLBS, 100 % MLBS, and 97 % MLBS and 100 % BPP), but weaker in our Supermatrix analysis (65 % ML BS). The ITS analysis by Vizzini and Ercole (2012) [2011] shows a single representative of Porpolomopis (as Humidicutis calyptriformis) on a separate, long branch emanating from the backbone that also gave rise to the Gliophorus clade.

Species included

Type: Porpolomopsis calyptriformis. Species included based on molecular data are Porpolomopsis lewelliniae (Kalchbr.) Lodge, Padamsee and Cantrell, comb. nov. (below), and three unnamed species from the USA, UK and Russia. Hygrocybe pura (Peck) Murrill) is included based on morphology.

Comments

Porpolomopsis was segregated from Hygrocybe by Bresinsky (2008) based on the color and absence of DOPA pigments. Most previous authors placed the type and related species in groups corresponding to Hygrocybe subg. Hygrocybe because of the conic pileus and the long lamellar trama hyphae with tapered ends (Fig. 12; Bon 1990; Candusso 1997; Kovalenko 1989, and tentatively by Singer 1986; Hesler and Smith 1963 as Hygrophorus sect. Hygrocybe, subsect. Hygrocybe; Herink 1959 as Godfrinia). Exceptions were Horak (1990) and Young (2005) who placed these species in Humidicutis, and Boertmann (2010) who placed H. calyptriformis in Hygrocybe subg. Humidicutis based on the pigments, absence or rarity of clamp connections in the context and pellis, and presence of spectacular toruloid clamp connections at the base of the basidia and basidioles. The molecular phylogenies detailed below place this clade as sister to Humidicutis.

Fig. 12 Porpolomopsis aff. calyptriformis lamellar cross section (DJL05TN80). Scale bar = 20 μm Full size image

Porpolomopsis lewelliniae (Kalchbr.) Lodge, Padamsee & S.A. Cantrell, comb. nov.

MycoBank MB MB804065.

Basionyn: Hygrophorus lewelliniae Kalchbr. (as ‘lewellinae’), Proc. Linn. Soc. N.S.W. 7(1–2): 105 (1882)

≡ Humidicutis lewelliniae (Kalchbr.) A.M. Young, Fungi of Australia: 159, (2005).

Type: AUSTRALIA, Western Port, Victoria, 14 June 1880, M.M.R. Lewellin, holotype RB MSS A11 (MEL).

Humidicutis (Singer) Singer, Sydowia 12(1–6): 225, 1959 [1958].

Type species: Humidicutis marginata (Peck) Singer (1959),

≡ Hygrocybe marginata (Peck) Murrill [as ‘Hydrocybe’], N. Amer. Fl. (New York) 9(6): 378 (1916),

≡ Hygrophorus marginatus Peck, Ann. Rpt. N.Y. State Mus. Nat. Hist. 28: 50 (1876).

Basionym: Tricholoma subg. Humidicutis Singer, Sydowia 2(1–6): 28 (1948).

Humidicutis is emend. here by Lodge to include species with a viscid pileipellis.

Pileus convex, convex-umbonate or conic, margin rarely and not deeply splitting; surface subhygrophanous, moist, rarely viscid (e.g., Humidicutis arcohastata and H. auratocephala), colors usually bright orange, yellow, pink, reddish purple or green but can be dull olivaceous or absent; lamellae thick, sinuate or broadly adnate, often with a decurrent tooth; odor absent or disagreeable; carotenoid pigments usually present, encrusting pigments may also be present on cuticular hyphae, not soluble in alkaline solutions; pileipellis hyphae parallel, prostrate, cylindric; basidia usually 5 or more times longer than the spore length; basidiospores hyaline, thin-walled, inamyloid, not metachromatic, ellipsoid or broadly ellipsoid, not constricted; lamellar trama subregular or regular, of hyphae < 150 μm long, rarely tapered, with right-angled septa; clamp connections absent in context and pellis, but toruloid clamps present at the base of basidia and/or basidioles.

Phylogenetic support

There is 100 % ML BS support for a monophyletic Humidicutis in the 4-gene backbone (Fig. 1; 1.0 B.P. Online Resource 6), and Supermatrix analyses (Fig. 2), 96 % MLBS support in the ITS-LSU analysis (Fig. 6), 77 % MLBS in the ITS analysis (Online Resource 3) and 83 % MLBS support in the LSU analysis (Fig. 3).

Species included

Type species: Humidicutis marginatus. Species included based on molecular phylogeny and morphology are Humidicutis auratocephalus (Ellis) Vizzini and Ercole (2012) [2011], two undescribed species from Puerto Rico and one from Belize. Species included based on morphology alone include H. arcohastata (A.M. Young) A.M. Young, H. bagleyi (A.M. Young) A.M. Young, H. helicoides (A.M. Young) A.M. Young, H. lilacinoviridis (A.M. Young) A.M. Young, H. luteovirens (Horak) Horak, H. multicolor (Horak) Horak, H. peleae Desjardin & Hemmes, H. poilena Desjardin & Hemmes and H. viridimagentea A.M. Young & Syme. It is uncertain whether H. taekeri (A.M. Young) A.M. Young and H. woodii (A.M. Young) A.M. Young belong here as their lamellar trama hyphae are fusiform and exceed 140 μm in length. Some species placed by Horak (1990) in Humidicutis cannot be verified without analysis of the lamellar trama and molecular sequence data.

Comments

Humidicutis was first described as a subgenus of Tricholoma by Singer (1948), then raised to generic rank by Singer in 1959 [1958]. It encompasses mostly brightly colored species that lack alkaline soluble pigments and lack clamp connections, except for toruloid clamps in the hymenium. Species of Humidicutis typically have rather short lamellar trama hyphae (Fig. 13) as compared to Porpolomopsis. While these appear as sister genera in the ITS-LSU and 4-gene backbone analyses, support for the branch that subtends both genera is lacking in the former and moderate (66 % MLBS and 0.67 B.P. in the latter. We retain separate genera here as they represent two strongly supported clades, and they can be separated morphologically by the lamellae which are broadly attached in Humidicutis versus adnexed to free in Porpolomopsis, and the long, parallel tramal hyphae which corresponds to a tendency for the pileus to split down through the lamellae in Porpolomopsis versus shorter, subregular trama hyphae and rarely splitting context in Humidicutis. Nevertheless, when treated within the genus Hygrocybe, Boertmann’s combination of subgen. Humidicutis in Hygrocybe (2010, Fungi of Northern Europe 1 (2nd ed): 17) is useful as it reflects the close relationship between these genera. Indeed, Young (2005) included species of Porpolomopsis in Humidicutis. If using the aggregate genus Hygrocybe s.l., the diagnosis of Hygrocybe subg. Humidicutis (Singer) Boertm. will need emending to include basidiomes with either splitting or non-splitting margins and regular or subregular lamellar context composed of either short or long trama hyphae.

Fig. 13 Humidicutis auratocephalus lamellar cross section (DJL05TN81, Tennessee, Great Smoky Mt. Nat. Park, USA). Scale bar = 20 μm Full size image

Humidicutis auratocephala (Ellis) Vizzini & Ercole, Micol. Veg. Medit.