Additional Generic Mergers in Bignoniaceae

Abstract

Five generic mergers in Bigoniaceae are proposed, largely as the result of palynological considerations. The proposed mergers are: Orthotheca with Xylophragma, Neves-Armondia with Pithecoctenium, Paradolichandra with Parabignonia, and both Hanburyophyton and Pachyptera with Mansoa. A new species, intermediate between Mansoa and Pachyptera, is described as M. ventricosa A. Gentry. New combinations required by the proposed mergers are: Xylophragma heterocalyx (Bur. & K. Schum.) A. Gentry, Mansoa lanceolata (DC.) A. Gentry, M. alliacea (Lam.) A. Gentry, M. erythraea (Dugand) A. Gentry, M. hymenaea (DC.) A. Gentry, M. kerere (Aubl.) A. Gentry, M. kerere var. incarnata (Aubl.) A. Gentry, M. parvifolia (A. Gentry) A. Gentry, M. standleyi (Steyerm.) A. Gentry, and Parabignonia chodatii (Hassler) A. Gentry. Transfer of Neves-Armondia cordifolia to Pithecoctenium necessitates a nomen novum, proposed as P. hatschbachii A. Gentry. The palynological considerations summarized in the preceding paper suggest several additional taxonomic changes besides supporting various generic mergers previously proposed. It is the purpose of this paper to formally propose five generic mergers based in large part on this palynological evidence. These generic mergers include Orthotheca with Xylophragma, Neves-Armondia with Pithecoctenium, Paradolichandra with Parabignonia, and both Hanburyophyton and Pachyptera with Mansoa. The latter merger makes possible generic assignment of a problematical new species sharing features of Pachyptera and Mansoa. ORTHOTHECA AND XYLOPHRAGMA Xylophragma heterocalyx (Bur. & K. Schum.) A. Gentry, comb. nov. Saldanhaea (?) heterocalyx Bur. & K. Schum. in Mart., Fl. Bras. 8(2): 254. 1897. TYPE: Brazil, Rio de Janeiro, Glaziou 14109 (P, holotype; C, K, isotypes). Orthotheca heterocalyx (Bur. & K. Schum.) Pichon, Bull. Soc. Bot. France 92: 226. 1945. Orthotheca was proposed by Pichon (1945) as a monotypic segregate from Saldanhaea primarily because of its single 3-colpate pollen grains with finely granular exine. Unfortunately, Pichon failed to realize that this is exactly the type of pollen found in Xylophragma, with which Orthotheca agrees in other respects as well. Salient features include interpetiolar glandular fields, dendroid pubescence (in part), rather contracted axillary inflorescences, short, blunt pseudostipules, and puberulous corollas with rather pointed lobes. Taxonomic significance of the unusual frilly margined calyx which characterized this species is not clear, but in some flowers of the type collection the calyx apex has broken off calypterately, and these differ hardly at all from those of Xylophragma pratense (Bur. & K. Shum. ex K. Schum.) Sprague and X. myrianthum (Cham.) Sprague. As is the case with so many of the poorly known monotypic genera of Big' This work was supported, both directly and indirectly, by various grants from the National Science Foundation, especially GB-40103. I am especially indebted to A. S. Tomb who did the palynological SEM work which formed much of the -basis for the proposed mergers. 2 Missouri Botanical Garden, Post Office Box 299, St. Louis, Missouri 63166. ANN. MISSOURI BOT. GARD. 66: 778-787. 1979. 0026-6493/79/0778-0787/$01.15/0 This content downloaded from 157.55.39.248 on Thu, 28 Jul 2016 05:23:38 UTC All use subject to http://about.jstor.org/terms 1979] GENTRY-GENERIC MERGERS IN BIGNONIACEAE 779 noniaceae which have been proposed, proper generic assignment makes specific, much less generic, recognition tenuous. The affinities of X. heterocalyx, a very rare species known only from the type collected in 1882, and a single recent collection [Herringer & Azevedo 9885 (UB) from Minas Gerais, Brazil], are obviously with Xylophragma pratense of eastern Bolivia and adjacent Brazil, Peru, and Paraguay. While it is conceivable that it may one day prove to be an extreme of X. pratense, the unusual calyx seems adequate for specific recognition in the absence of either geographical or morphological intermediates, and a new combination is in order, though retention of Orthotheca is not. PACHYPTERA, HANBURYOPHYTON, AND MANSOA Mansoa DC., Rev. Bign. (Bibl. Univ. Geneve) 12. 1838. LECTOTYPE: M. hirsuta