Phaseolus leptostachyus Bentham (1837: 72) [clade B; sect. Falcati Freytag].

TYPE: WF Karwinski s.n. (LECTOTYPE: M; ISOLECTOTYPE: SI) .

The original publication about P.anisotrichos is of 1838 (von Schlechtendal 1838), therefore this name falls into synonymy. There would thus be no reason to maintain the latter as a separate species in the list of “Vascular Plants of the Americas” (Tropicos 2020). Note the specimen at the Darwinion is a small fragment of the original of M (from a loan?). It is a common species in openings of oak, pine-oak and tropical deciduous forests, from almost sea level to 2,500 m (Fig. 9). The synonymy proposed elsewhere (Delgado-Salinas 1985) for P. opacus Piper (1926) with P.leptostachyus makes sense. Five botanical varieties were recognized in this species (Freytag & Debouck 2002), while in author’s view they represent the natural variation of this widespread species.

Specimens: MEXICO. Sonora: IL Wiggins 6995 (DS-264709). Tamaulipas: E Estrada-CastillÓn 2726 (CAS-794254). Chiapas: A Delgado-Salinas 823 (DS-719855). GUATEMALA. Huehuetenango: DG Debouck 3073 (AGUAT). Jalapa: PC Standley 76999 (F-1202124). HONDURAS. Francisco Morazán: LO Williams 17292 (MO-1737913). EL SALVADOR. Santa Ana: JL Linares 1070 (LAGU). La Libertad: AC del Cid 1681 (ITIC). NICARAGUA. Nueva Segovia: DG Debouck 3198 (O-V2147547). Granada: P Levy 1096 (P). COSTA RICA. Guanacaste: DG Debouck 3288 (USJ-111503). Puntarenas: F Oviedo-Brenes 2776 (USJ-111843).