4 6 



THE CACTACEAE. 



Subgenus 1. CYLINDROPUNTIA. 



Includes the many-jointed species in which none of the joints is at all flattened. 



Series 1. RAMOSISSIMAE. 



The series consists of a single bushy species, with slender joints, the nearly flat tubercles 

 diamond-shaped and contiguous, the acicular spines, when present, usually only i at an areole. 



1. Opuntia ramosissima Engelmann, Amer. Journ. Sci. II. 14:339. 1852. 

 Opuntia tessellata Engelmann, Proc. Amer. Acad. 3: 309. 1856. 



Frutescent, bushy, sometimes 2 meters high, the branches gray, often widely spreading, and 9 cm. 

 long; tubercles low, slightly convex, 4-angled to 6-angled, giving the surface an appearance of being 

 covered with diamond-shaped plates; leaves ovoid, 

 i to 3 mm. long, acute; areoles on young shoots 

 circular, with white or tawny wool and pale glochids, 

 the upper part in age compressed into the narrow 

 slit between the two adjoining tubercles, the lower 

 part depressed-linear, with a slightly elevated border; 

 spines often wanting, but when present abundant, 

 usually one at each areole, rarely 2, porrect, acicular, 

 sometimes 6 cm. long, usually reddish when young, 

 covered by loose, yellow, papery sheaths; flowers, 

 including ovaries, 3 to 4 cm. long; sepals subulate, 

 similar to the leaves of the ovary, but longer; petals 

 greenish yellow, tinged with red, obovate, aristulate, 

 about i cm. long; stamens greenish yellow; anthers 

 orange-colored; style and stigma-lobes cream-colored; 

 ovary narrowly obconic, covered with emarginate 

 tubercles, the areoles bearing wool and long glochids, 

 but no spines; fruit dry, obovate, 2 to 2.5 cm. long, 

 covered with clusters of weak, slender spines, appear- 

 ing like a bur; seeds few, white, 5 mm. broad. 



Type locality: In California, near the Colo- 

 rado River. 



Distribution: Southern Nevada, western 

 Arizona, southeastern California, northwestern 

 Sonora and probably northeastern Lower Cali- 

 fornia. 



The flowers of this species have been described as purple, apparently erroneously. 



This species is found in the most arid deserts of the southwestern part of the United 

 States, usually growing on low hills, and is confined chiefly to the lower Colorado; it is 

 here rather inconspicuous and might easily be overlooked. It is one of the least succulent 

 species of the genus, the terminal shoots soon becoming hard, and hence the plant is 

 difficult to propagate from cuttings, and is rarely found in greenhouse collections. 



Opnntia tessellata cristata Schumann (Monatsschr. Kakteenk. 8 : 70. 1898) is a striking 

 monstrosity which Schumann has described and figured. 



Illustrations: Cact. Journ. i : pi. [i]; Cycl. Amer. Hort. Bailey 3 : f. 1549; Pac. R. Rep. 

 4 : pi. 21 ; 24, f. 20, all as Opuntia tessellata. 



Figure 54 represents a spiny branch drawn from a specimen sent by Mr. S. B. Parish 

 from Barstow, California, in 1915; figure 55 shows a portion of an unarmed branch sent 

 by the same collector from the same locality. 



Series 2. LEPTOCAULES. 



Bushy species, with slender joints, the ultimate ones 4 to 1.5 mm. thick, often readily detached; 

 the flowers small. 



Inhabitants of the southwestern United States, Mexico, northern South America, and 

 one species in Santo Domingo. 



FIGS. 54, 55. Opuntia ramosissima. Xo.75- 



