320 PROCEEDINGS OF THE AMERICAN ACADEMY. 



2. Spines light-colored, conspicuously compressed and very broad at the base. 



31. M. dysocarpa, Benth. Shrub with stems angled : pinnae 6 to 

 12 pairs; rhachis elongated, slightly armed with small scattered spines; 

 leaflets 7 to 16 pairs, densely silky-villous almost tomentose, somewhat 

 cinereous, oblong, 4 to 6 (to 8) mm. in length, acutish : spikes at first 

 dense, at length laxer, 2.5 to 7.5 cm. long exclusive of the much shorter 

 2)eduncle, subpaniculately aggregated at the summit of the stem : calyx 

 and pods tomentose, the former 2 mm. or more in length, turbinate below; 

 the latter 2.5 to 5 cm. long, about 6-seeded, more or less constricted 

 between the seeds, sharply acuminate, unarmed or provided with a few 

 short curved spines on one edge. — Benth. in Gray, PI. Wright, i. 62, & 

 Trans. Linn. Soc. xxx. 414, t. 66; Gray, PI. Wright, ii. 51; Coult. 

 Contrib. U. S. Nat. Herb. ii. 97. — Rocky hills, W. Texas, Wright, no. 

 163; New Mexico, Thurber, no. 1104, Wright, no. 1040; 3Iiss Mul- 

 ford, nos. 387, 696; Arizona, Rothrock, no. 511, Rushy, no. 113a, 

 Lemmon, no. 2690 ; State of Durango, Mexico, Palmer, no. 418 (coll. 

 of 1896). 



= = Stem covered with minute sessile or stipitate glands. 



32. M. adenantheroides, Benth. Stem puberulent, glandular- 

 punctate : spines recurved : pinnae about 9 pairs ; leaflets about 9 pairs, 

 obliquely oval, obtuse, 3-nerved, pubescent, pale beneath : spikes fascicled 

 by 3's ; flowers pubescent. — Benth. in Hook. Lond. Jour. Bot. v. 88 ; 

 & Trans. Linn. Soc. xxx. 416. Acacia adenantheroides, Mart. & Gal. 

 Bull. Acad. Brux. x. pt. 2, 310. — On calcareous and gneissic mountains 

 of Sola and Yolotepeque, Cordillera of Oaxaca, at 2153 to 2307 m., 

 Galeotti, no. 3208. Description compiled. Near this species must 

 stand two differing yet doubtfully distinct plants collected in the moun- 

 tains of Oaxaca by Nelson, and represented by his nos. 2078 and 1479. 

 Both differ from the above description in having only 3 to 5 pairs of' 

 pinna?, but without fuller knowledge of Bentham's species can neither 

 be identified with it nor positively excluded from it. 



H_ 4- 4- Leaflets 15 to 40 pairs, oblong : fruit not 1 cm. in breadth : unarmed tree. 



33. M. puberula, Benth. Pinnte 5 to fO pairs; leaflets 15 to 40 

 pairs, crowded, oblong, rigid, obtuse, 4 to 5 mm. long: spikes axillary, 4 

 to 5 cm. long: fruit stipitate, flat, pubescent. — Benth. in Hook. Lond. 

 Jour. Bot. V. 88, & Trans. Linn. Soc. xxx. 413. — Zimapan, Th. 

 Couller, and " New Spain" Herb. Pavon, ace. to Benth. Description 

 compiled. 



