It is important to stress here that we did not observe in C. schwackeanus any well developed petals' tube as originally described by Mez. Also, serrulation on the sepals and the yellow coloration of the petals, as reported by Smith & Downs, were not confirmed.
Cryptanthus schwackeanus was described in 1891 by Carl Mez, on the basis of a specimen collected by A Glaziou at Pico de Itabira do Campo, Minas Gerais State. When sterile its unusual appearance (leaves suberect, neither narrowed at base nor undulate on the margins, with protruded but delicate spines) gives a clear impression of an Orthophytum species.
In nature, this species presents populations well distributed in some mountains of Minas Gerais State. It grows preferably in the vegetation complex called rupestral fields, in altitudes over 700 meters. The floristical composition of this complex reflects the very special local conditions involving climate, topography, soil and drainage characteristics. The main constituents are herbaceous or shrubby species perfectly adapted to rupicolous habit. There, C. schwackeanus was found on the rocky outcropping, sometimes under direct sunlight, where it assumes a reddish coloration of its subcoriaceous leaves.
Besides the few historical collections, which include the isotype deposited in the herbarium of the Museum National of Rio de Janeiro (R),we examined freshly collected plants from two distinct regions: Ouro Preto, nearer to the type locality, and Conceicao do Mato Dentro-Jaboticatubas. Comparing the specimens from these two places, although with almost identical floral features, we observed an interesting discordance in the leaf conformation, probably due to microclimate influence, The sunny, open, and drier region of Ouro Preto produces coriaceous and smaller plants, with leaves usually not longer than 10 cm. On the other hand, at the Conceicao do Mato Dentro- Japoticatubas region the abundance of forests provide amesophytic habitat for this species, which shows more numerous and longer leaves (ca. 20cm long) of a delicate texture. On the basis of all these materials a description was elaborated. —SeeJ. Crypt. Soc.
