308 PROCEEDINGS OF THE AMERICAN ACADEMY. 



Subg. 2. EuMiMOSA, DC. (as modified by Benth.). Flowers perfect 

 or polygamous : stamens ia all equal in number to the lobes of the 

 corolla. — Mem. Leg. xii. 418, & Prodr. ii. 425, in major part; Benth. 

 Trans. Linn. Soc. xxx. 388, 389. 



* Pinnae 1 pair ; leaflets very large, ovate or ovate-lanceolate to obovate, 1 or 

 more commonly 2 pairs upon each secondary rhachis, but the inner leaflet of 

 the lower pair mostly much reduced or even wanting. — Series Sensitivce, 

 Benth. 1. c. 388, 390. 



-t- Stem glabrous or in J\f. manzanilloana slightly strigose. 



-M. Unarmed shrubs or trees. 



2. M. sesquijugata, J. D. Smith. Low shrub branched from 

 the base : leaflets elliptic-oblong or lance-oblong, rounded or acutish at 

 the apex, coriaceous and reticulate-veiny, glabrous and lucid above, 

 appressed-setose but soon glabrate and glaucous beneath, 15 to 20 mm. 

 long: petioles slender, essentially glabrous: peduncles downwardly 

 strigose: flowers purplish, tetramerous. — Bot. Gaz. xiii. 74 (1888). — 

 In rock-fissures near Santa Rosa, Dept. Baja Verapaz, Guatemala, 

 altitude 1525 m., July, 1887, von Tuerckheim (no. 1327 of J. D. Smith's 

 valuable Guatemalan set). 



3. M. Goldmanii. Small tree, 3 to 6 m. high : glabrous through- 

 out except for the setose-ciliate margins of the leaflets, stipules, and 

 bracts : stems woody, covered with grayish brown bark : petioles fili- 

 form ; leaflets obovate-oblong, obtuse or rounded, mucrouate, rather 

 thin, green above, perfectly glabrous and slightly glaucescent beneath, 

 12 to 18 mm. long, 6 to 8 mm. broad ; margin ciliate with conspicuous 

 appressed or incurved stramineous bristles ; rhachises devoid of bristles ; 

 stipules subulate, attenuate, slightly ciliate: peduncles filiform, usually 

 equalling or often exceeding the petioles, fascicled on short or unde- 

 veloped secondary axes; heads numerous, globose, 12 mm. in diameter; 

 flowers 4-merous, puri^lish white : legume unknown. — Collected by 

 Nelson & Goldman between Juchitan and Chivela, Oaxaca, at 50 to 275 

 m. altitude, 1895, no. 2628 (herb. Gray and herb. U. S. Nat. Mus.). 

 This species differs from any of the other Mexican and Central Ameri- 

 can species of the Sensitivce in its perfectly glabrous peduncles and 

 petioles, also by having the lower surface of the leaflets devoid of 

 setfc as well as any trace of pubescence. It is evidently near the 

 South American 31. glaucescens, Benth. and M. angusta, Benth., but 

 these from description have larger leaflets and are woody only at 

 the base. 



