Vol. 34, pp. 41-42 March 31, 1921 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



TWO NEW LEGUMES FROM MEXICO AND COSTA 



RICA. 



BY C. V. PIPER. 



In the course of a critical study of the genus CanavaHa it was 

 found necessary to examine also the related genera. The two 

 following plants seem to be undescribed species. 



Phaseolus chiapasanus, sp. nov. 



Herbaceous, climbing, slender-stemmed, the whole plant turning black 

 in drying; stems terete, sparsely pilose with rusty hairs; petioles terete, 

 rusty pilose, longer than the leaflets; stipules oblong-quadrangular, striate, 

 acuminate, glabrous above, pubescent beneath, 1 cm. long; stipels narrowly 

 oblong-lanceolate, striate, curved, pubescent beneath, 3-4 mm. long; peti- 

 olules 5-6 mm. long, rusty pubescent; leaflets thin membranaceous, broadly 

 ovate to orbicular, conspicuously acuminate with the tip apiculate, three- 

 nerved from the rounded base, sparsely strigillose above, more so beneath 

 especially on the nerves, 7-10 cm. long; flowers in loose slender bracteate 

 racemes; bracts ovate-lanceolate, acuminate, glabrous above, rusty pubes- 

 cent beneath, 4-5 mm. long, the lower ones entire, the upper divided to the 

 base into 2 or 3 segments; pedicels slender, pubescent, 5-10 mm. long, each 

 bearing a single bracteole at the base of the calyx; gland at base of pedicel 

 expanded, 2-lobed; calyx campanulate, 8-9 mm. long, rusty pubescent with 

 appressed coarse hairs, the lobes much shorter than the tube, the upper lip 

 notched, shorter than the lower, the lobes obtuse, the lower lip 3-lobed, the 

 lateral ones obtuse, the median longer and acute; corolla about 3 cm. long; 

 standard orbicular, emarginate at apex, reniform at base, short-unguiculate, 

 2.5 cm. long, 2 cm. broad, rather firm in texture, a linear gland in the mid- 

 dle toward the base ; wings as long as the body of the keel, unguiculate, the 

 stalk and middle portion thickish, the terminal third thin and expanded, 

 a short lobe near the middle ; keel thickish, semicircularly curved, the nar- 

 now beak in two complete coils about 5 mm. broad; stamens diadelphous; 

 ovary linear, rusty pubescent; style bearded on the under side toward the 

 tip; stigma scarcely enlarged, lateral, covered with retrorse papillae. 



Finca Mexiquito, Chiapas, Mexico, C. A. Purpus 6881, Sept., 1913 (type 

 in the U. S. National Herbarium, sheet No. 567.182). 



5— Proc. Bioi>. Soc. Wash., Vol.. .34, 1921. (41) 



