ROBINSON. — SPERMATOPHYTES OF MEXICO. 473 
to 30 pairs linear-oblong, 5 to 8 mm. long, 1.6 mm. wide, acutish, oblique 
at the base, finely appressed-pubescent upon both sides : flowers capitate, 
heads globose, 1.3 cm. in diameter; peduncles filiform, 1.5 cm. long, 
borne.by twos and threes in the axils of the upper leaves: calyx turbinate- 
campanulate, scarious, slightly cuspidate-toothed, 0.8 mm. long: corolla 
2.3 mm. long, glabrous, not conspicuously ribbed: stamens 8 or 10: 
pod 4.5 em. long, 1.2 em. broad, unarmed, glabrous, dark colored, ob- 
lanceolate, acute, thickish; valves not segmented. — Collected by Dr. 
J. N. Rose in the foothills of the Sierra Madre, near Colomas, State 
of Sinaloa, Mexico, 21 July, 1897, no. 1805. Type in herb. U. S. 
Nat. Museum; fragment in herb. Gray. To this species I should refer 
also Dr. Rose’s no. 3157, collected on a road between Acaponeta and 
Rosario. While it is more copiously armed it shares all important char- 
acteristics with the plant from Colomas. The species is readily distin- 
guished by its smooth unjointed fruit and axillary inflorescence. 
«~ Mimosa ionema. Shrub or small tree 3 to 5 m. high; branches 
unarmed, terete or nearly so, puberulent ; branchlets green, angled and 
costate, tomentulose : stipules filiform, 8 mm. long, tomentulose under a 
lens ; petioles angled, straight, puberulent-tomentulose, 4 to 6 cm. long, 
equalled by the foliar rachis; pinnae 4 to 6 subremote pairs, 5 cm. long, 
the lower ones commonly alternate; stipels 1 mm. long; leaflets about 
15 pairs, oblong, obtuse, green and nearly or quite glabrous upon bot 
surfaces, slightly paler beneath, oblique at the base, excentrically 1-nerved, 
pinnately veined, 1 cm. long, 3 to 4 mm. broad: flowers loosely spicate, 
spreading or somewhat deflexed ; spikes fascicled by 3’s and 4’s in the 
axils of the upper leaves, ascending, 6 em. long, on penduncles 2 to 3 cm. 
in length: corolla white or pale yellow, 2.5 mm. long, cleft to below the 
middle, without conspicuous nerves or ribs, glabrous; segments 4 to 5, 
lance-oblong, acutish: stamens 8 to 10; filaments violet-tinged: fruit 
(immature) narrowly oblong, acute at both ends, thin, glabrous, 5 cm. 
long, 7 mm. broad, about 8-seeded. — Collected by C. G. Pringle in the 
valley below Cuernavaca, Mexico, altitude 1,230 m., 17 October, 1900, 
no. 8377. Type in herb. Gray. 
imosa Watsoni. Fruticose and probably scandent: stems sub- 
terete, tomentulose chiefly along six longitudinal lines, these bearing 
minute approximate subequal very short recurved spines: branchlets 
grayish-tomentose: petioles (including the rachis) 5 cm. long, rigid, 
angled, armed laterally and ventrally by 2 or 2 lines of recurved spines, 
tomentulose especially along the armed angles; pinnae 2 pairs; the 
Ower bearing 1 or 2 pairs of leaflets, the upper with 2 or 3 pairs; 
