Espostoopsis in Krainz, Kakteen: 38-39, C Va. 1968 sec. Zappi & Taylor 2020
- Type: Espostoopsis dybowskii
Category B. The genus is monophyletic based on phylogenetic studies that support the clade based on a sufficiently dense or even complete sampling, or support a monotypic genus as a distinct lineage, but do not provide a new taxonomic treatment at the species level. In many cases, older classical taxonomic synopses or a monographic treatment exist for these genera providing a reliable assessment of the species included.
Monotypic genus, endemic to the caatinga of Bahia, SE Brazil. Hernández-Hernández & al. 2011 found E. dybowskii within an unsupported Trichocereeae clade, as sister to Rauhocereus (no support), while Schlumpberger & Renner 2012 found E. dybowskii as sister to Micranthocereus densiflorus with 78% MLBS support. Espostoopsis is therefore not closely related to the Andean genus Espostoa, a relationship that had been suggested earlier based on the strong morphological similarities of the two genera.A
A. Korotkova, N., Aquino, D., Arias, S., Eggli, U., Franck, A.R., Gómez-Hinostrosa, C., Guerrero, P.C., Hernández, H.M., Kohlbecker, A., Köhler, M., Luther, K., Majure, L.C., Metzing, D., Müller, A., Nyffeler, R., Sánchez, D., Schlumpberger, B.O. & Berendsohn, W. G. 2021: Cactaceae at Caryophyllales.org – a dynamic online species-level taxonomic backbone for the family. – Willdenowia 51: 251-270