ROBINSON. — SPECIES OF MIMOSA. 319 



Guadalajara, Jalisco, Palmer, no. 449 (coll. of 1886) in fruit, Pringle, 

 nos. 2914, 4459, in flower; near Tamazulapam, Oaxaca, Nelson, 

 no. 1962. 



"Var. malacocarpa. Fruit fulvous-tomentose but nearly or quite 

 devoid of prickles. — Collected by E. W. Nelson, between Amolac, 

 Puebla, and Sochi, Guerrero, altitude 1200 to 1260 m., 28 November, 

 1894, no. 2023, and by /. N. Rose, at Bolanos, Jalisco, September, 1897, 

 no. 2917. Indistinguishable from the typical form except by its strik- 

 ingly different fruit. The original specimens of Acacia fasciculata 

 described by Kuuth were not in fruit, so it is impossible to say which 

 form was the orieinal one. Under the circumstances it seems best to 

 adopt as the typical form the one of which the fruit was first described 

 (see Wats. 1. c). 



h. Calyx more distinctly toothed, 1 to 1.5 mm. long, a tliird to half the length 

 of the corolla: spikes shorter and thicker. 

 1. Spines mostly dark-colored, not greatly compressed. 



29. M. ccelocarpa. Shrub, armed with small scattered straight 

 spines ; bark of branches gray : pinnse 6 to 8 pairs ; leaflets oblong, acut- 

 ish, green on both sides, appressed-puberulent upon margin and lower 

 surface, 3 mm. long, eccentrically 1-nerved, thin ; stipules setaceous : spikes 

 mostly geminate in the upper axils, moderately loose ; peduncles slender, 

 14 to 18 mm. long: buds obovoid : flowers white with roseate tinge: 

 corolla 4-parted: stamens 1 cm. in length: pods oblong-linear, acute at 

 both ends, unarmed, toraentulose, 4 or 5 cm. long, 5 mm. broad ; margins 

 thickened ; segments distinctly concavo-convex, the seed more or less 

 prominent within the concavity. — Collected at Topolobampo, Sinaloa, 

 Mexico, by Dr. Edivard Palmer, 15 to 25 September, 1897, no. 187. 

 Near the next, but distinguished by its peculiar fruit, longer peduncles, 

 looser spikes and thinner leaflets. Types in hei'b. Gray and herb. U. S. 

 Nat. Mus. 



30. M. Wrightii, Gray. Shrub, armed with scattered spines: 

 branchlets tomentulose, angulute ; leaves much as in the last but thicker, 

 varying from tomentose to subglabrous : peduncles shorter, 1 to 1.5 cm. 

 long : spikes short and at first very dense ; buds subglobose, tomentose : 

 pods rusty-tomentose, unarmed ; margins thick ; segments not distinctly 

 concavo-convex. — PI. Wright, ii. 52; Benth. Trans. Linn. Soc. xxx. 

 417. — Mountains of Arizona, Palmer, Pringle, Tourney, nos. 37, 38; 

 Sonora, Wright, no. 1041 (type) ; Chihuahua, Pringle, no. 359, Hart- 

 man, no. 732. A greener and usually less tomentose plant than the 

 next species. 



