Phaseolus tenellus Piper (1926: 696) [clade A; sect. Minkelersia (Martens & Galeotti) Maréchal, Mascherpa, & Stainier].

TYPE: G Arsène 8310 (HOLOTYPE: US-1003657 n.v.; ISOTYPES: BM, F-48495, GH-64112, MO-541731, SI).

A member of the Minkelersia found in openings of pine-oak forest at 2100–2900 m.

Specimens: MEXICO. Zacatecas: CL Díaz-Luna 2352 (MICH-1180118). Michoacán: A Delgado-Salinas 1775 (K-1041785). México: GB Hinton 6528 (GH).