428 
vini 1 to 2.5 em. apart, with slender short bright reddish-brown bristles: 
spines 1 or 2, elongated (3.5 to 7.5 em.), white (sometimes dusky at 
base and apex), teretish, straight, slender, flexile, suberect or spread- 
ing (in upper pulvini the upper one porrect and the rest deflexed), and 
1 to 4 shorter (1 to 3 cm.) white inferior ones: flowers yellow, 6 to 7.5 
em. broad: fruit oblong, with deep umbilicus, 2.5 to 3 cm. long: seeds 
very irregular, with narrow margin and deeply notched hilum, 3 to 4 
mm. broad (JU. Cact. Mex. Bound. t. 75, f. 14)—Type, the Wright 
specimens in Herb. Mo. Bot. Gard. 
Sandy ridges on the Rio Grande from E] Paso, Texas, northward into 
adjacent New Mexico. 
Specimens examined: NEw Mexico (Wright of 1852, Dona Ana): 
Tisxas ( Wright of 1851-52, EK] Paso): also cult. in Mo, Bot, Gard, 1870. 
29. Opuntia setispina Engelm.; Salm, Hort. Dyck. 239 (1850). 
Ascending, with small suborbicular glaucous joints not over 5 cm, 
long: pulvini crowded (6 to 8 mm. apart), with yellowish bristles: 
spines 4 to 10, very slender (like the bristles), 1 to 3 longer (2.5 to 3.6 
em.) and subangular, 3 to 7 shorter and more or less detlexed: flowers 
and fruit unknown.—Type, Wislizenus of 1846 in Herb. Mo, Bot. Gard. 
“Pine woods in mountains west of Chihuahua.” 
Specimens examined: CHIHUAHUA ( Wislizenus of 1846), 
30. Opuntia filipendula Engelm. Syn. Cact. 294 (1856). 
Ascending from a long thick tuberiferous root, 1.5 to 3 dm. high, 
with orbicular or obovate or oblanceolate thin bluish glaucous joints, 
3.5 to 7.5 long by 2.5 to 5 cm. broad: pulvini 8 to 12 mm. apart, with 
white wool, greenish-yellow very slender numerous penicillate bristles 
(becoming very conspicuous), with or without spines: spines (if pres- 
ent) white, 1 or 2 elongated setaceous deflexed ones (not rarely sub- 
angular and twisted) 2.5 to 5 em. long, and 1 or 2 smaller lower ones: 
flowers purplish, 6 em. broad: seeds very thick, with narrow but thick 
aud obtuse margins, 3.5 to 4 mm. broad. (JI, Cact. Mex. Bound. t. 
68)-——Type, the Wright specimens in Herb. Mo. Bot. Gard. 
Alluvial bottoms of the Rio Grande from the Pecos to I] Paso, Texas, 
and southward into Chihuahua. 
Specimens examined: TEXAS ( Wright of 1852; Schott of 1855): CHI- 
HUAHUA (Pringle 147; EB. A. Mearns of 1892, “‘ Mesquite Spring”). 
(4) Procumbent or ascending: joints rather small: spines stout, subterete, white or dusky, 
or none: fruit clavate. 
31. Opuntia mesacantha Raf.; Seringe, Bull. Bot. Gen. 216 (1830). 
Opuntia cespitosa Raf, 1. c. 
Opuntia rafinesquit Engelm. Syn. Cact. 295 (1856). 
Opuntia vulgaris rafinesquii Gray, Man. ed. 2, 186 (1856). 
Opuntia vulgaris in part of Amer. authors, not Haw. 
Diffuse, from a fibrous root, with obovate or suborbicular very green 
joints 7.5 to 12.5 em. long bearing elongated subulate spreading leaves 
6 to 8 mm. long: pulvini 1.8 to 2.5 cm. apart, with slender reddish- 
