316 PROCEEDINGS OF THE AMERICAN ACADEMY. 
= = Leaflets 7 to 10 mm. in length. 
21. M. distachya, Cav. Covered throughout with a fine close 
puberulence or tomentulose pubescence: spines stout, recurved, solitary 
on the internodes, directly beneath the leaves or removed from them 
or rarely absent: pinne about 3 pairs; leaflets 2 to 5 pairs, obovate, 
not crowded, finely and closely pubescent upon both surfaces: spikes 
geminate from the axils, pedunculate, rather short and dense. — Icon. 
iii. 48, t. 295; Benth. Trans. Linn. Soc. xxx. 417. — Mazatlan, Sinaloa, 
Rose, no. 1393; Cordillera of Oaxaca, Galeotti, no. 3240, acc. to Benth. 
(Also S. Am.). Dr. Rose’s specimen shows the hitherto unknown 
legume to be oblong, 3.6 cm. in length, about 5-seeded, sharply tipped, 
puberulent and unarmed or armed on the margin with a few scattered 
short weak prickles. 
++ ++ Leaflets and younger parts of stem glabrous or merely puberulent. 
= Valves of fruit hispid with numerous tawny bristles. 
t~ 22. M. Brandegei. A spreading shrub, 2 to 3 m. high: spines 
single or double, stout, recurved, borne mostly near the middle of the 
internode: pinne 3 to 4 pairs: leaflets 2 to 4 pairs, obovate, nearly 
concolorous, glabrous above, puberulent (under lens) beneath, 9 % 
15 mm. long, rounded but slightly mucronate at the summit ; rhachises 
sparingly pubescent: spikes single or fascicled by 2’s or 3’s, peduncles 
3 or 4 cm. long: flowers white or nearly so: young fruit narrowly 
oblong, minutely pubescent and also bristly-setose. — JZ distachya? 
Brandegee, Proc. Calif. Acad. Sci. ser. 2, iii. 133, not Cay. — San 
José del Cabo, Todos Santos, La Paz, Lower Calif., Brandegee, no. 184 
(herb. Gray, herb. Brandegee). 
= = Fruit glabrous, unarmed. 
28. M. laxiflora, Benru. Shrub, glabrous or nearly 80, with 
striate branches and stoutish recurved spines: pinnw 3 or 4 pairs; leaf- 
lets 3 to 5 pairs, obovate, glabrous or early glabrate, 7 to 10 mm. long; 
about 3-nerved: spikes solitary or geminate, lax; flowers essentially 
glabrous, white: pods oblong, thin, glabrous, stramineous, unarmed, 
~ about 8-seeded. — Benth. in Hook. Lond. Jour. Bot. v. 93, & Trans. 
Linn, Soc. xxx. 418. ? Acacia prosopoides, DC. Prodr. ii. 4605 
A. DC. Calques des Dess. t. 210.— Gattunas, Sierra de la Union, neat 
_ the southern boundary of New Mexico, Schott; mountains of N. W. 
Sonora, Pringle, 12 August, 1884; S. W. Chihuahua, Palmer, no. 4 
(1885); near Guaymas, Palmer, no. 169 (coll. of 1887) ; Sonora Alta, 
Th. Coulter, no. 522, acc. to Hemsl. 
