172 



THE CACTACEAE. 



188. Opuntia velutina Weber in Gosselin, Bull. Mus. Hist. Nat. Paris lo: 3S9. 1904. 



Opunlia nelsonli Rose, Smiths. Misc. Coll. 50: 516. 1908. 

 Stems I to 4 meters high; joints flattened, oblong to pear-shaped in outline, 15 to 20 cm. long 

 by 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, becoming white in age, very unequal, the longer ones 3 to 4 

 cm. long; bristles many, yellow, becoming brownish; flowers rather small; petals yellow, i to 3 cm. 

 long ; ovary pubescent, bearing many yellowish brown bristles ; filaments red ; stigma-lobes pale green ; 

 fruit "dark red." 



Type locality: In Guerrero, Mexico. 

 Distribution: Southern Mexico. 



Plate XXXII, figure 3, represents a flowering joint of a plant collected at Tehuacan, 

 Mexico, by Dr. MacDougal and Dr. Rose in 1906. 



189. Opuntia wilcoxii sp. nov. 



A tall, bushy plant, i to 2 meters high, very much branched; joints oblong, thinnish, large, 2 cm. 

 long, dark green, more or less purplish about the large areoles, finely puberulent; glochids numerous, 

 long, yellow; spines i to 3, one very long (5 to 6 cm. long), porrect, white or somewhat yellowish; 

 flower, including ovary, 6 cm. long, yellow; petals oblong, mucronate; ovary bearing few large 

 areoles, these filled with brown wool and yellow glochids; filaments short; style thick, 2 cm. long, 

 with 10 stigma-lobes; fruit pubescent, 4 cm. long. 



Very common on the hills in the coastal plain of west- 

 ern Mexico from southern Sonora to southern Sinaloa, 

 Mexico, where it was frequently collected by Rose, 

 Standley, and Russell in 1910; their No. 13546, with 

 flower, from Fuerte, Sinaloa, is selected as the type of 

 the species. It is named for Dr. Glover B. Wilcox, who 

 first sent in living specimens in 1909. 



Figure 211 represents a joint of the type specimen. 



To this series belong two plants which we have not 

 been able to identify but are here briefly characterized : 



The first, a very peculiar species, collected by Rose, 

 Standley, and Russell, March 14, 1910 (No. 12853), o" 

 the dry hills near Alamos, Sonora, Mexico, is unlike any of 

 the described species. It is living both in Washington 

 and New York, but it has not done well in cultivation. 

 It may be described as follows: 



Bushy; joints oblong, thickish, pale green in color, with very 

 short puberulence, nearly or quite spineless ; glochids yellowish 

 or greenish, numerous; young areoles brown in the center, 

 white-woolly in the margin; flowers and fruit not known. 



Dr. H. H. Rusby collected the second species on the Balsas River, southern Mexico. 

 It comes from the region of 0. velutina, but we do not know its flowers. It may be described 

 as follows: 



Joints oblong, 18 cm. long, but cultivated specimens smaller, usually obovate, dark green; 

 spines few, short, at first white; young areoles large, bordered with white wool, bearing the spines 

 and glochids from the center. 



lyiving specimens are growing in the New York Botanical Garden under No. 3281 1. 



Series 17. TOMENTOSAE. 



Tall, erect, pubescent or puberulent species, with flat persistent joints, the spines, when present, 

 white. We know three species, natives of Mexico and Guatemala. 



Fig. 2 1 1 . — Opuntia wilcoxii. X0.4. 



