CACTUS FAMILY 155 



the lower side, 2-4 cm. in diameter, entirely clothed with a dense mat of bright yellow spines, 

 turning gray to nearly black in age; ribs 18-25, 2-3 mm. high, somewhat tuberculate; spines 

 10-30 at an areole, slender-acicular, 1-6 of central spines sometimes 6 cm. long; flowers 2-2.5 

 cm. broad when expanded, the outer perianth-segments obtuse, obovate 5-8 mm. long, lemon- 

 yellow, tinged with green, inner segments narrower, oblong, 8-10 mm. long, almost or quite 

 devoid'of the greenish tinge; fruit globular, 2-3.5 cm. in diameter, covered with spines 0.5-1.5 

 cm. long, dry; seeds oblong, black, shining, pitted, about 2.5-3 mm. long. 



On coastal bluffs and hillsides never more than a few miles from the sea, Lower and lower Upper Sonoran 

 Zones; from the vicinity of San Diego and Santa Catalina Island, California, southward a few miles beyond 

 Rosari'o, Lower California. April-May. 



4. ECHINOCEREUS Engelm. in Wisliz. Mem. Tour. North. Mexico. 91. 1848. 



Low erect, prostrate, or pendent, usually cespitose plants with globose to cylindric 

 stems, which are considerably elongated if prostrate or pendent over rocks or cliffs. 

 Spines of flowering and sterile areoles similar, acicular, subulate, terete or flattened, 

 crowded or distant. Flowers usually (always in ours) large, diurnal, campanulate to short 

 funnelform, the tube and ovary spiny. Stigma-lobes green. Fruit thin-skinned, spiny, 

 though spines easily removed when mature. Seeds black, tuberculate. [Name Greek, 

 referring to the spiny fruit.] 



A genus of about 60 (65-70) species in the western United States and Mexico. Type species, Echinocereus 

 viridiflorus Engelm. 



Stems in loose clusters, 3-20; flowers rose-purple. 1. E. Engelmannii. 

 Stems crowded in compact mounds, 10-300; flowers pink or scarlet. 



Flowers cerise-pink; stems 10-60. 2. E. Muneii. 



Flowers scarlet; stems up to several hundred. 3. E. mojavensis. 



1. Echinocereus Engelmannii (Parry) Riimpler. Saints' Cactus. Fig. 3328. 



Cereus Engelmannii Parry ex Engelm. Amer. Jour. Sci. II. 14: 338. 18S2. 



Cereus Engelmannii var. variegatus Enselni. & Bigelow in Engelm. Proc. Amer. Acad. 3: 283. 18S6. 



Echinocereus Engelmannii Rumpler in Forster, Handb. Cact. ed. 2. 805. 1885. 



Echinocereus Engelmannii var. variegatus Riimpler in Forster, Handb. Cact. ed. 2. 806. 1885. 



Loosely branched cespitose plant with 3-20 ascending cylindric branches 1-3.5 dm. high, 5-8 

 cm. in diameter. Ribs 11-14, obtuse, 5-10 mm. high; areoles nearly circular; radial spmes 

 8-15, 1-1.5 cm. long, appressed-spreading, rigid, straight or slightly curved; central spines 3-6, 

 stout, more or less twisted and curved, white to brown, terete to slightly flattened, 3-4 (7) cm. 

 long; flowers 5-8 cm. long, as broad or broader when expanded, reddish purple; perianth- 

 segments oblong, acuminate, 3-4 cm. long; fruit ovoid to oblong, 2.S-3 cm. long covered with 

 clusters of acicular spines and woolly felt borne in the a.xils of acuminate scales 3-5 mm. long ; 

 seeds black, globose, 1-1.5 mm. in diameter, tuberculate. 



Gravelly or stony hillsides and washes, Lower Sonoran Zone; Inyo County through Mojave and Colorado 

 Deserts, California, to southern Utah, Arizona, Lower California, and Sonora. April-May. 



2. Echinocereus Munzii (Parish) L. Benson. Munz's Nigger-head. Fig. 3329. 



Cereus Munzii Parish, Bull. S. Calif. Acad. 25: 48. 1926. 



Echinocereus Engelmannii var. Munzii Pierce & Fosb. Bull. S. Calif. Acad. 32: 123. 1933. 



Echinocereus Munzii L. Benson, Amer. Journ. Bot. 28: 361. 1941. 



A cespitose plant with 10-60 oblong stems 10-20 cm. long, compactly crowded in cushion-like 

 clumps. Ribs 10-20, undulate, low; spines all white to ashy gray, radials 8-16,_ acicular to nar- 

 rowly subulate, spreading and interlocking, unequal, 2-3 cm. long; central spines 1^, stouter 

 than the radials, 2.5-5 cm. long; flowers campanulate, 4-7 cm. long, 3-4 cm broad when ex- 

 panded, cerise-pink; perianth-segments obtuse; floral tube and ovary clothed with clusters ot 

 unequal, white acicular spines 5-12 mm. long, embedded in short, felt-like white wool; truit 

 obovoid 2-2.5 cm. long, red, clothed with clusters of acicular readily deciduous spines; seeds 

 rugulose. 



Dry stony slopes along the lower margins of the Arid Transition Zone; desert side of the San Bernardino 

 and San Jacinto Mountains, California, southward into northern Lower California. May. 



3. Echinocereus mojavensis (Engelm. & Bigelow) Rumpler. Mojave Nigger- 



heads. Fig. 3330. 



Cereus mojavensis Engelm. & Bigelow in Engelm. Proc. Amer. Acad. 3: 281. 1856. 

 Cereus Bigelovii Engelm. Pacif. R. Rep. 4: pi. 4. fig. 8. 1856. 

 Echinocereus mojavensis Rumpler in Forster, Handb. Cact. ed. 2. 803. 1885. 



A cespitose plant with sometimes several hundred (to 800) closely crowded globose to oblong 

 pale green spiny stems 5-20 cm. long, 4-7 cm. in diameter, forming rounded mounds. Ribs («) 

 10-13, 5-6 mm. high, undulate, obtuse and becoming indistinct toward the base of the stem; 

 spines white to gray, the radial spines 3-10, acicular, 1-2.5 cm. long, spreadmg and interlocking, 

 straight or slightly curved; central spines 1-3, subulate, 2.5-5 cm. long porrect to spreading 

 more or less flexuous ; flowers 5-7 cm. long, scarlet, narrower than long when expanded; 



