148 CACTACEAE 



2-8 mm. long, light yellowish brown ; flowers yellow to reddish ; fruit dry, 4-6 cm. long, nar- 

 rowly ovate, narrowly tuberculate, the areoles 3-4 mm. in diameter, filled with white wool and 

 radiating, acicular, yellowish brown glochids 3-9 mm. long that conceal the surface; seeds 

 flattened-ovoid, smooth, turgid, 3.5-5 mm. long, yellowish white. 



Infrequent in loose sandy or gravelly soil, upper part of Lower and lower part of Upper Sonoran Zones; 

 southern Nevada to the eastern Mojave and western Colorado Deserts, and the Little San Bernardino Moun- 

 tains, California. May. 



9. Opuntia Treleasei J. M. Coult. Trelease's Tuna. Fig. 3309. 



Opuntia Treleasei]. M. Coult. Contr. U.S. Nat. Herb. 3: 434. 1896. 



Opuntia basilaris var. Treleasei Tourney in Bailey, Cyclop. Hort. 1147. 1901. 



Opuntia Treleasei var. Kernii Griff. & Hare, N. Mex. Agr. Exp. Sta. Bull. 60: 81. 1906. 



Low, spreading at the base, 2-3.5 dm. high, some of the branches of 2-4 erect joints. Joints 



broadly obovate, 8-15 cm. long, fleshy, 1-1.5 cm. thick, minutely papillose but glabrous, pale 



blue-green; areoles numerous, about 5-12 mm. apart, elliptic, 2-2.5 mm. wide, 3-4 mm. long, 



filled with sordid-yellow glochids 1-5 mm. long, a tuft of white wool at the base of young 



areoles, spineless, or more frequently with 1-3 divergent to subporrect acicular, sordid-yellow to 



brown spines 4-15 mm. long; flowers orchid- or rose-colored, 4-5 cm. broad; petals obovate, 



obtuse, 1.5-2 cm. long; fruit dry, broadly ovate to subglobose, bearing large areoles filled with 



dirty yellow glochids, dingy wool and the upper ones 3-10 rigid spines, 3-8 mm. long ; seeds 6-7 



mm. in diameter, rather turgid. 



Dry grassy hills and valley floor, Lower Sonoran Zone; in the southern San Joaquin Valley south and east 

 of Bakersfield, Kern County, California. April-May. 



10. Opuntia basilaris Engelm. & Bigelow. Beaver-tail Cactus. Fig. 3310. 



opuntia basilaris Engelm. & Bigelow in Engelm. Proc. Amer. Acad. 3: 298. 1856. 



Low, prostrate to erect plant, usually growing in clumps, branching mostly from the base, 

 seldom over 2-5 dm. high. Joints orbicular to broadly obovate, 7-25 cm. long, short-puberulent, 

 pruinose to glabrate in age, occasionally tinged with red or purplish ; areoles numerous, circular 

 to elliptic, 2-3 mm, in diameter, spineless, filled with dingy wool when young, this soon replaced 

 by erect yellowish brown glochids 1-3 mm. long; flowers borne on upper margins of joints, 

 somewhat clustered, 10-15 cm. broad, deep rose to rose-purple, a conspicuous velvety sheen on 

 the petals ; fruit dry at maturity, 5-6 cm. long, globose to obovoid, spineless, areoles and glochids 

 as on the joints; seeds 6-10 mm. broad, more or less angled. 



Arid mountain slopes and desert washes, Lower Sonoran and Arid Transition Zones; Mojave and Colorado 

 Deserts and adjacent mountain slopes to southern Utah, Arizona, and northern Sonora. March-June. 



Opuntia basilaris var. ramdsa Parish, Bull. Torrey Club 19:92. 1892. Joints oblong to narrowly obo- 

 vate, 5-8 cm. wide up to 30 cm. long; stems frequently 3-6 joints high, branching freely above. Northwestern 

 Los Angeles County eastward to the western edge of the Mojave Desert, south to western Riverside and north- 

 eastern San Diego Counties; Caliente and Democrat Hot Springs, Kern County, California. 



Opuntia whitneyana E. M. Baxter, Calif. Cactus 37. 1935. A low plant with quite thick, obovate red- 

 tinged joints 4-15 cm. long, and small (2 mm. diameter) deeply sunken areoles; glochids short, scarcely reaching 

 surface of joint; flowers with numerous, crinkly, erose, red petals. Rocky mountain sides and talus slopes on 

 eastern side of the Sierra Nevada in Inyo and Mono Counties, California. Transition Zone. 



Opuntia whitneyana var. albiflora E. M. Baxter, Calif. Cactus 39. 1935. Differing from the species in 

 having more profusely branching green stems and white flowers. "Rounded mountain top 'flats' in the eastern 

 Sierra Nevada Mountains near Mount Whitney." 



11. Opuntia brachyclada Griff. Short- jointed Beaver-tail. Fig. 3311. 



opuntia brachyclada Griff. Proc. Biol. Soc. Wash. 27:25. 1914. 

 Opuntia basilaris var. brachyclada Munz, Man. S. Calif. Bot. 325. 1935. 



Low cespitose plant forming compact clumps, 1^ joints high. Joints thick, obovate to nearly 

 clavate-cylindrical, 3-6 cm. long, minutely and closely puberulent, deep green, often red-tinged; 

 areoles 2-3 mm. in diameter, spineless, filled with gray wool when young, with yellow-brown 

 glochids 1-3 mm. long in age ; flowers few, 4-6 cm. broad, rose to rose-purple ; fruit dry, obovoid. 

 2-3 cm. long, truncate at the apex, bearing areoles and glochids similar to those of the joints. 



Upper Sonoran and Arid Transition Zones; on desert slopes of the San Gabriel and San Bernardino Moun- 

 tains. April-June. 



Opuntia brachyclada subsp. humistrata (Griff.) Wiggins & Wolf. (Opuntia humistrata Griff. Bull. Torrey 

 Club 43: 83. 1916.) Joints 6-12 cm. long, obovate, thick but distinctly flattened, more freely branching, 4—6 

 joints high; flowers few, these and fruit as in the species. Interior cismontane valleys from the San Bernardino 

 Valley to Temescal Canyon, Riverside County, California. 



12. Opuntia fragilis (Nutt.) Haw. Pigmy Tuna. Fig. 3312. 



Cactus fragilis Nutt. Gen. PI. 1:296. 1818. 



Opuntia fragilis Haw. Suppl. Syn. PI. Succ. 82. 1819. 



Opuntia brachyarthra Engelm. & Bigelow in Engelm. Proc. Amer. Acad. 3: 302. 1856. 



Opuntia fragilis var. brachyarthra J. M. Coult. Contr. U.S. Nat. Herb. 3: 440. 1896. 



Opuntia fragilis var. caespitosa Hortus in Bailey, Cyclop. Hort. 2363. 1916. 



Opuntia fragilis var. tuberiformis Hortus, loc. cit. 



Opuntia Columbiana Griff. Bull. Torrey Club 43: 523. 1916. 



Tunas fragilis Nwd. & Lunell, Amer. Midi. Nat. 4: 479. 1916. 



Low, spreading plant, sometimes forming matted clumps 1-2 dm. high, 3^ dm. in diameter 



