Since Thiemann’s death in 2001, the operation has been run by his widow, Fatima, who lives on the property in a large house the color of pink sand, and their adult daughters, Magda and Roselinde. They wander daily among the low-growers: Astrophytum capricorne, which could be mistaken for a groundhog devouring a buttercup, and Echinocereus pectinatus, which resembles a bushel of small rosy penises. They measure the tall varieties, many of which grow only two inches a year, including Cephalocereus senilis, which appears like a giant hairbrush that has been used on an Afghan hound, and Neoraimondia herzogiana, a Bolivian cultivar that is a favorite among the visitors — usually landscape designers and horticulturists — because, Magda says, ‘‘it looks like the ones in the Spaghetti Westerns that you slice into for water to save the hero’s life.’’ The oldest and tallest is a perception-bending specimen of Pachycereus pringlei that Thiemann brought over on the boat with him as a mere sliver. At 26 feet tall, it is not for sale at any price.

Each year, more people find their way, somehow, to this lunar landscape, so the sisters are planning a small cafe. ‘‘Simple and wild,’’ Magda says. Just a few seats and some shade, a place to sip tea and stare into the thorny abyss.