330 PROCEEDINGS OP THE AMERICAN ACADEMY. 



hrachycarpa, Benth. in Hook Jour. Bot. ii. 130, iv. 415. — Tropical 

 America: S. Mexico, Huasteca, Ervendberg ; Guatemala, nos. 211 »&; 

 6105 of J. D. Smith's sets. 



A noteworthy form, coll. at Mazatlan, Sinaloa, Lamb, No. 329 

 (distrib. as M. Ervendbergii) has straighter spines and longer less pubes- 

 cent unarmed peduncles. 



-1- -1- -t- Corolla not striate : pubescence not strigose : spines scattered, not seri- 

 ate: pods short, 1-3-jointed, narrow, not over 5 mm. in breadtli. 

 ++ Densely villous with long spreading yellowish hairs. 



63. M. camporum, Benth, Prostrate, nearly herbaceous, scarcely 

 armed : stipules ovate, striate : pinnae about 6 pairs ; leaflets numerous, 

 narrowly oblong : heads large, many-flowered, oval, including the long 

 stamens 2.5 cm. in diameter; bracts long and conspicuous in the young 

 heads, imbricated, ciliate, tawny-villous : pods 6 to 12 mm. long, 4 mm. 

 broad. — Benth. in Hook. Jour. Bot. ii. 130, iv. 403, 3f. jlaviseta, Benth. 

 in Hook. Lond. Jour. Bot. v. 90. 3f. ceschynomenes, Benth. Bot. Sulph. 

 89. — Acaponeta, Tepic, Rose, nos. 3116, 3295; Realejo, Nicaragua, 

 Hinds, Sinclair, ace. to Hemsl. (Trop. Am.) 



■M. ■>-*■ Hispid with a few scattered setose spines, and sparingly pubescent. 



64. M. pusilla, Benth. Prostrate annual: pinnae 1 to 9 pairs, 

 leaflets 6 to 12 pairs, oblong, 4 mm. long, heads small, few-flowered, 6 

 mm. in diameter ; peduncles 1 cm. or less in length : pods 2-3-jointed, 

 setulose on margin or valves, 3 or 4 mm. in breadth. — Bot. Sulph. 90. — 

 Acapulco, Palmer, no. 9 (coll. of 1894-1895); Realejo, Sinclair, Hinds, 

 ace. to Benth. & Hemsl. Although I have seen no authentic specimens 

 of this species, I cannot doubt that it is represented by Dr. Palmer's 

 specimen. 



^_ H_ 4_ H_ Corolla not striate : pubescence usually strigose : pods 1-ce -seeded, 8 



to 14 mm. broad. 

 ++ Prostrate, herbaceous or nearly so : leaf-rhachis unarmed : pods 2-4-seeded. 



Q5. M. strigillosa, Torr & Gray. Often rooting at the joints, 

 scarcely or not at all armed : heads large, oval, usually long-peduncled : pods 

 2.5 cm. in length, oblique at the summit, acutish, setose throughout. — Fl. 

 i. 399; Chapm. Fl. 115. — Pine barrens and hummock lands of Florida, 

 westward to W. Texas : adjacent Mexico, Berlandier, Gregg, Palmer, 



•w- ++ Ascending or erect, suffruticose : leaf-rhachis armed with opposite acicular 

 spines between the pinnae ; stipels also spinescent : pods short 1-3-seeded, 

 obovate with broad oblique summit. 

 66. M. dormiens, H. & B. Whole habit and foliage of the fol- 

 lowing more abundant species, but softer appressed-villous rather than 



