Rosaceae

Plants of the Rose Family

If you have ever buried your nose into an apple, rose, strawberry, or cherry blossom, then you know the Rose family. Roses have alternate leaves, which vary from simple to trifoliate, palmate, or pinnate. The whole leaves or smaller leaflets are frequently more or less oval-shaped with serrated edges, which is a good secondary pattern for recognizing the Rose family. As for the flowers, there are typically 5 (rarely 3 to 10) separate sepals and a similar number of petals. There are a minimum of 5 stamens, but often many more, usually in multiples of five. Many flowers of the Rose family, especially those of the Rose subfamily, have several to numerous simple pistils, or the pistils may be united at the base, with the styles separate, making a single compound pistil with numerous styles. Either way, the result is a distinctive, fuzzy-looking center surrounded by lots of stamens. Plants of the Rose family form many different fruits, varying from fleshy fruits to various false fruits, dry seeds, capsules, or follicles.



Worldwide, there are about 100 genera and 3,000 species. About 50 genera are found in North America. The Rose family produces many edible fruits. Tannins are common in the vegetation, giving astringent properties. Cyanide compounds are found in the leaves and fruits of some species.



In the early 1900s, botanists reclassified the former Spirea, Plum, and Apple families as subfamilies within the Rose family. In response, Robert Frost poemed, "The rose is a rose and was always a rose. But the theory now goes that the apple's a rose, and the pear is, and so's the plum, I suppose. The dear [Lord] only knows what will next prove a rose. You, of course, are a rose - but were always a rose."



Taxonomists have since determined that the Spiraea, Plum, and Apple subfamilies did not represent genetically distinct lines, but should more properly combined as a single subfamily, now known as the Almond subfamily, Amygdaloideae. When you have a specimen in hand, then read through each of the subfamilies to narrow down the choices for identification.