Stenandriopsis S.Moore

Manzitto-Tripp, Erin A., Darbyshire, Iain, Daniel, Lucinda A. McDade Thomas F. & Kiel, Carrie A., 2022, Revised classification of Acanthaceae and worldwide dichotomous keys, TAXON 71 (1), pp. 103-153 : 143

Stenandriopsis S.Moore in J. Bot. 44: 153. 1906

– Type: Stenandriopsis thompsonii S.Moore.

= Achyrocalyx Benoist in Bull. Soc. Bot. France 76: 1036. 1930, syn. nov. – Type: Achyrocalyx decaryi Benoist.

Vollesen (1992) transferred OW species previously treated within Stenandriopsis to Stenandrium , which had previously been treated as a NW genus, citing a lack of morphological evidence for their separation. However, the NW and OW clades are clearly separated phylogenetically ( McDade & al., 2005) and so Stenandriopsis is resurrected here. Combinations are available for all but two of the species of OW Stenandrium ; as such, the new combinations are made below.

McDade & al. (2005) sampled one of the three species of Achyrocalyx in their phylogenetic analysis of Acanthoideae and found it to be resolved within the Stenandriopsis clade, related to the two sampled species of Malagasy Stenandriopsis . Achyrocalyx was separated from Stenandriopsis by Benoist (1930) on the basis of having a bilabiate corolla versus corolla with five subequal lobes. However, McDade & al. (2005) noted that several species of Stenandriopsis have a zygomorphic corolla and, further, that plants of Achyrocalyx share with Malagasy Stenandriopsis the character of having leaves in pseudowhorls, a trait that Vollesen (1992) used in placing African and Malagasy species of Stenandriopsis into different sections. Hence, Achyrocalyx is best placed in Stenandriopsis and the new combinations are made here.