Two More Cephalium-Bearing Cacti

Abstract

Many cephaliumand pseudocephaliumbearing cacti described in this issue are closely related to either Melocactus or Pilosocereus, but there are two striking taxa that are considered to be distantly related: Espostoopsis dybowskii and Facheiroa cephaliomelana subspecies estevesii. Espostoopsis dybowskii is an enigmatic monotypic genus. With cream colored spines and pure white hairs, its four-meter-tall stems branch only from the base and start growing a cephalium when about 1.5–2.0 meters tall. While similar in appearance to the Peruvian genus Espostoa, it may not be closely related. While both genera are known for their densely hairy stems (not true in all Espostoa species), longerhaired wooly lateral cephalia, off-white funnelform flowers, and tall stems that seldom branch except at the base, these genera live thousands of kilometers apart from one another. Molecular systematists have yet to publish a phylogeny incorporating the DNA of Espostoopsis, but when one does we may finally understand where this cactus sits on the family tree. Whatever the case, it is a gorgeous plant in habitat and a fast grower in cultivation. Facheiroa is a genus of three species: F. cephaliomelana, F. ulei, and F. squamosa. Unlike Espostoopsis, Facheiroa is now considered a relative of Espostoa/Vatricania by biologists, although hobbists tend to disregard them as straggly weeds. The first two species have long lateral cephalia, which the third lacks. Despite the bad rap this genus receives, Facheiroa cephaliomelana subspecies estevesii, which we saw atop a large hill of bambui limestone near Iuiu, Bahia, was the prettiest plant I saw in eastern Brazil. Even without these magnificent columnar cacti, this would have been a fantastic habitat with Euphorbia attastoma, succulent Bombaceae in the genera Cavanillesia, and Ceiba, fantastic bromeliads, Melocactus levitestatis, Quiabentia zehntneri, and the ubiquitous Pilosocereus pachycladus. Esostoopsis dybowskii on the quartz massif at Serra Escura, Bahia, but one of many isolated Espostoopsis populations.