Senna pallida var. palmeri (Britton & Rose) H. S. Irwin & Barneby

Peiranisia palmeri Britton, sp. nov
Nearly glabrous, the branches slender, sparingly pubescent above. Stipules only about 1.5 mm. long; leaves about 8 cm. or shorter, glabrous, or the petiole and rachis sparingly pubescent ; gland short-clavate, borne between the lower pair of leaflets, and also more slender ones on the inflorescence at the base of the pedicels; leaflets 3-5 pairs distant, membranous, rather faintly pinnately veined, 1-2.5 cm. long, obtuse or acutish; peduncles axillary, slender, 1-3-flowered, 1-2 cm. long; pedicels slender, about as long as the peduncles; sepals suborbicular, rounded, about 8 mm. long; petals about twice as long as the larger sepals; legume rather broadly linear, sparingly short-pubescent, shining, 10-12 cm. long, about 8 mm. wide, slender-stipitate, impressed between the seeds, the apex rounded.
Vicinity of Acapulco, Guerrero, October 1894 to March 1895, E. Palmer 260.