Weberocereus

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 : 11

The Weberocereus clade

Weberocereus is depicted as polyphyletic. A clade containing five species, including W. tunilla (F.A.C. Weber) Britton & Rose —the type species—is supported with 1 PP, 82% MLBS, 80% JK, but W. glaber and W. tonduzii are resolved at different positions within Selenicereus . The Weberocereus clade has two subclades: W. tunilla and W. trichophorus are resolved as sisters with maximum support. These two species are morphologically similar, with thin (less than 15 mm in diameter), pendent stems, campanulate flowers, and purple fruit pulp. The second subclade contains Weberocereus frohningiorum Ralf Bauer , W. imitans and W. rosei (Kimnach) Buxbaum , but is supported by only 0.5 PP, 54% MLBS and is not found by the MP analysis, although W.rosei and W. imitans are highly supported as sister species. These three species constitute the Eccremocactus group sensu Bauer (2003a) and are morphologically characterized by flattened or 3-ribbed stems, and white fruit pulp. Among the hylocereoid clade, W. imitans and W. rosei share the flat stems with Selenicereus anthonyanus , and together the three species were included in Cryptocereus ( Backeberg 1959) . However, our results show that Weberocereus species are not related to S. anthonyanus . The flat stem character state is convergent between clades within Hylocereeae and also occurs in Disocactus , Epiphyllum and Pseudorhipsalis . Weberocereus is morphologically heterogeneous in the current circumscription and is not well separated from Hylocereus or Selenicereus . The main difference is that the flowers of Weberocereus are smaller (less than 7 cm in length) compared to those of Hylocereus / Selenicereus . Weberocereus glaber and W. tonduzii (type species of Werckleocereus ) represent the Werckleocereus group ( sensu Bauer 2003a ) and are resolved within the Hylocereus / Selenicereus assemblage, with which they share 3-ribbed stems and white nocturnal flowers with dark spiny pericarpels. So, morphologically, they do fit well within the Hylocereus / Selenicereus assemblage.