884 CONTEIBUTIONS FEOM THE NATIONAL HERBARIUM. 



62. Opuntia durangensis Britt. & Rose, Smiths. Misc. Coll. 50: 518. 1908. 

 Durango. 



Joints broadly obovate, about 20 cm. long, 16 cm. broad, pale green, glabrous 

 or minutely puberulent, bearing numerous areoles, these 1 to 2 cm. apart, 

 elevated ; spines 3 to 5 at an areole, short, 1.5 cm. long or less, pungent, 

 spreading, yellow but in age becoming darker ; glochids brown, 2 to 3 mm. 

 long ; flowers yellow, 5 cm. long ; petals broad, apiculate ; ovary 3 to 4 cm. 

 long, finely pubescent, bearing manj' areoles with numerous glochids and a 

 few spines ; fruit white or red ; seeds about 3 mm. broad. 



63. Opuntia atropes Rose, Smiths. Misc. Coll. 50: 518. 1908. 

 Morelos, the type from Tautepec. 



Plants 1 to 3 meters high, much branched; joints oblong to obovate, 20 

 to 30 cm. long, deep green, softly pubescent; young joints somewhat glossy; 

 areoles circular, filled with short tawny wool ; young spines white or yellowish ; 

 old spines 3 to 6 cm. long, somewhat angled, standing almost at right angles 

 to the joints, dark yellow or brown at the base, much lighter and often 

 white above ; glochids numerous, long, yellow ; petals reddish ; ovary pubescent, 

 covered with large cushion-like areoles bearing long glochids near the top 

 but with few spines or none, truncate at apex. 



64. Opuntia affinis Griffiths, Proc. Biol. Soc. Washington 27: 27. 1914. 

 Oaxaca. 



Arborescent, sometimes 2 meters high or more; joints obovate, 35 cm. long, 

 broadly rounded above and gradually narrowed below, densely silky ; areoles 

 obovate, 3 mm. long, 3 cm. apart; glochids light straw-colored, 3 mm. long; 

 spines 1 to 5 in the upper areoles, straw-colored, becoming white, the longest 

 3 cm. long, divergent, flattened, angular, twisted; flowers dull dark red in 

 bud, about 3 cm. in diameter ; petals 2 to 2.5 cm. long ; ovary subglobose, deeply 

 pitted, 15 to 17 mm. in diameter, with small brown areoles 4 mm. apart; fruit/ 

 subglobose, small, red. 



65. Opuntia macdougaliana Rose, Smiths. Misc. Coll. 50: 516. 1908. | 

 Opuntia micrarthra Griffiths, Monatsschr. Kakteenk. 23: 130. 1913. ' 

 Southern Mexico, the type from TehuacS-n, Puebla. 



Plants about 4 meter.s high, with a distinct cylindric trunk branching from 

 near the base ; joints oblong. 30 cm. long by 8 to 10 cm. broad, softly pubescent ; 

 areoles distinct, small; spines generally 4, one much longer (2.5 to 4 cm. long), 

 somewhat flattened, yellowish, becoming whitish in age; glochids short, nu- 

 merous, yellow ; fruit globular to oblong, 5 cm. long, the surface divided into 

 diamond-shaped plates, red, with a broad deep cup at apex, the numerous 

 small rounded areoles filled with clumps of yellow glochids, very rarely with 

 one or two spines. 



66. Opuntia velutina Weber; Goss. Bull. Mus. Hist. Nat. 10: 389. 1904. 

 Opuntia nclsonii Rose, Smiths. Misc. Coll. 50: 516. 1908. 



Southern Mexico; type from Guerrero. 



Stems 1 to 4 meters high; joints flattened, oblong to obovate, 15 to 20 cm. 

 long, 10 to 15 cm. broad near the top, pubescent, pale, yellowish green in 

 herbarium specimens; areoles 2 to 3 cm. apart; spines 2 to 6, yellow, becom- 

 ing white in age, very unequal, the longer ones 3 to 4 cm. long ; bristles many, 

 yellow, becoming brownish; flowers rather small; petals yellow, 1 to 3 cm. 

 long; ovary pubescent, bearing many yellowish brown bristles; filaments red; 

 fruit " dark red." 



