ROBINSON. — SPERM ATOPHYTES 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. loug, 

 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 cm. long, 1.2 cm. 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 ; branchletsi 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 both 

 surfaces, slightly paler beneath, oblique at the base, excentricallv 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 cm. 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 "». 

 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. 



Mimosa Watsoni. Fruticose and probably scandent: stems sub- 

 terete, tomentulose chiefly along six longitudinal lines, these bearing 

 minute approximate subequal very short recurved spines: branchleta 

 grayish-tomentose : petioles (including the rachis) 5 cm. long, rigid, 

 angled, armed laterally and ventrally by 2 or 3 lines of recurved spines, 

 tomentulose especially along the armed angles; pinnae 2 pairs; the 

 lower bearing 1 or 2 pairs of leaflets, the upper with 2 or 3 pairs ; 



