Aporocactus

Korotkova, Nadja, Borsch, Thomas & Arias, Salvador, 2017, A phylogenetic framework for the Hylocereeae (Cactaceae) and implications for the circumscription of the genera, Phytotaxa 327 (1), pp. 1-46 : 10

The Aporocactus clade

Aporocactus is weakly supported as monophyletic (0.6 PP, --MLBS, 54% JK). Its position within the Hylocereeae remains unresolved. Nevertheless, our results are congruent with those of Cruz et al. (2016) who likewise found Aporocactus distant from Disocactus . Aporocactus was originally established as a genus by Lemaire (1860) but it was not generally accepted afterwards and was included in Cereus [a more detailed classification history of Aporocactus was given by Hunt (1989)]. Only Britton & Rose (1920) reinstated the genus Aporocactus . Later authors followed the latter proposal (see e.g. Backeberg 1959, Bravo-Hollis 1978) until Barthlott (1991) included Aporocactus in Disocactus because all the species form hybrids with other Disocactus taxa (W. Barthlott, pers. comm. to N. K.).

Cruz et al. (2016) argued for reinstating Aporocactus as a separate genus and we follow this view (see Taxonomic synopsis). Aporocactus is endemic to Mexico, where it preferably inhabits tropical montane cloud forests. Apart from a further clarification of relationships of Aporocactus within the Hylocereeae , work is needed to more reliably delimit species within the genus, since only two species are accepted ( Bauer 2003a) while the morphological variation among populations is significant and still needs to be evaluated to support species recognition.