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4. OPUNTIA Tourn. 
Articulated much branched plants of various shapes, low and pros- 
trate or erect and shrub-like, with young branches bearing small terete 
subulate early deciduous leaves and in their axils an areola with nu- 
merous short easily detached bristles and (usually) stouter spines (all 
barbed), mostly large diurnal flowers with very short cup-sbaped tubes 
on joints of the previous year and on the same areole with the spines, 
spreading or rarely erect petals, ovary with bristle-bearing areolz in 
- the axils of small terete deciduous sepals, and a succulent or dry trun- 
cate berry marked with bristly or spiny areola.—Ours all have broad 
obovate or obcordate petals. 
§ 1. Joints compressed (glabrous except in No. 11): fruit fleshy (except in No. 12): seed with 
a prominent bony margin. 
*Suberect : spines very numerous, colored: berry small, subglobose. 
1. O. Strigil Eng. Plant 6dm. high: joints ovate or orbicular, 10 to 12.5 em. long: 
pulvilli crowded ; spines 5 to 8, 2.5 em. long or less, radiate and deflexed, reddish- 
brown with yellow tip: berry 12 to 14 mm. long, red, broadly umbilicate.—Between 
the Pecos and El Paso. 
** Erect or procumbent: joints large: spines few, stout, compressed, mostly colored : berry 
larger, mostly ovate, 
2. O. Englemanni Salm. Erect, 12 to 18 dm. high: joints obovate, 3 dm. long or 
less: pulvilli remote, bearing unequal rigid straw-colored bristles and 1 to 3 com- 
pressed straw-colored spines reddish at base and 2.5 to 3.5 cm, long: flowers yellow 
(reddish within), 6.5 to 7.5 em, across, with globose ovary : berry obovate, broadly 
umbilicate, usually 5em. long. (Incl, 0, dulcis Eng.).—Common throughout southern 
and western Texas. This seems to be the common “ prickly pear” of Texas, though 
all the flat-jointed Opuntias bear that name. The joints are commonly spoken of as 
“leaves,” and form an important food for grazing animals, under the name of 
“nopal.” The “nopal leaf” is also much used for poultices, ete. Var. ? CYCLODES 
Eng., on the upper Pecos, has orbicular joints, stouter and mostly single spines, and 
a small globose berry. 
3. O. macrocenta Eng. Ascending, 6 to 9 dm. high: joints suborbicular, thin, 
12.5 to 20 em. in diameter: pulvilli somewhat remote, bearing short, slender, fulvous 
bristles, the uppermost only having 1 or 2 very long (5 to 7.5 em.) blackish subcom- 
pressed spines: flowers yellow, with ovate ovary.—Sand-hills of the Rio Grande near 
E] Paso. 
4. O. pheacantha Eng. Diffuse, ascending: joints obovate, thick, glaucescent, 
10 to 15 em. long: pulvilli somewhat remote, bearing longer slender straw-colored or 
grayish-brown bristles, and almost all with 2 to 5 more or less compressed grayish- 
brown spines 2.5 to 5 cin. long: flowers yellow, about 5 cm, in diameter, with a short 
ovary: berry cuneate, pear-shaped, 3 to 3.5 cm. long, slender, much contracted at 
base go as to appear almost stipitate.—Sandy places near E] Paso. 
5. O. Camanchica Eng. Prostrate and extensively spreading: joints ascending, © 
suborbicular, 15 to 17.5 em. long: pulvilli remote, mostly bearing few straw-colored 
or fulvous bristles, and 1 to 3 compressed grayish-brown (paler at tip) spines, the 
upper ones elongated, suberect, the rest deflexed, 3.5 to 7.5 cm, long: berry ovate, 
large, broadly umbilicate.—On the Llano Estacado. 
6. O. tortispina Eng. Similar in size and habit to the last: pulvilli subremote, 
with the 3 to 5 spines larger, angled, often twisted, white, with 2 to 4 slenderer ones.—~ 
On the Camanche plains, east of the Llano Estacado. 
