156 CACTACEAE 



perianth-segments broadly obovate, obtuse to retuse ; stigma-lobes green ; ovary and fruit clothed 

 with groups of short acicular spines embedded in white felt ; fruit oblong, 2-3 cm. long. 



Rocky hillsides, cliffs, mountain valley floors, and mesas in the desert ranges, Lower Sonoran to lower Arid 

 Transition Zones; Inyo County south to San Bernardino County, California, east to Nevada, Arizona, and San 

 Felipe Desert, Lower California. May. 



5. ECHINOCACTUS Link & Otto, Verb. Ver. Beford. Gartenb. 3: 420. 1827. 



Single or cespitose plants with globose or cylindrical stems clothed with dense mat of 

 wool or naked at the apex. Ribs few to many. Areoles large, very spiny. Flowers borne 

 on the crown of the plant, yellow or pink, medium in size; flower-tube covered with 

 imbricate, persistent, pungent scales. Ovary clothed with narrower scales having axillary 

 mats of wool. Fruit densely white-woolly, dry, thin-walled, oblong. Seeds black, smooth, 

 shining or papillose; hilum subbasal. [Name Greek, meaning hedgehog cactus, referring 

 to the rigid spines.] 



A genus of about 12 species (narrower sense) of Mexico and the southwestern United States. Type species, 

 Echinocactui platyocanthus Link & Otto. 



1. Echinocactus polycephalus Engelm. & Bigelow. Nigger-beads. Fig. 3331. 



Echinocactus polycephalus Engelm. & Bigelow in Engelm. Proc. Amer. Acad. 3:276. 1856. 

 Echinocactus polycephalus var. flavispinus Haage Jr. Monatss. Kakteenk. 9: 43. 1899. 



Solitary when very young, but soon forming clumps of 3-60 heads, each globular to oblong- 

 ovoid, 1-3 (7) dm. high. Ribs 10-21, 2-3 cm. high, tuberculately irregular ; areoles 10—12 mm. in 

 diameter; radial spines 8-10, unequal, 2.5-5 cm. long, woolly and reddish when young, glabrate 

 and gray to black in age, subulate, flattened ; central spines 3-5, stouter than the radial ones, 

 more or less annulate, curved but not hooked, 3-10 cm. long ; flowers 5-6 cm. long, yellow ; 

 perianth-segments linear-oblong, entire ; scales on flower-tube and ovary small, obscured by 

 wool ; fruit 1 .5-2.5 cm. long, dehiscing by a basal pore ; seeds angulate, dull black, 3-4 mm. long. 



Rocky hillsides and gravelly slopes. Lower Sonoran Zone; deserts of San Bernardino County, California, 

 to southern Utah, Arizona, northern Sonora, and Lower California. Feb. -March. 



6. FEROCACTUS Britt. & Rose, Cactaceae 3: 123. 1922. 



Globular or cylindrical, often massive cacti. Ribs thick and prominent, often slightly 

 twisted spirally about the stem. Spines heavy, straight or hooked, the central ones usually 

 flattened and annulate. Areoles large, having flowers just above the spine clusters and 

 more or less woolly-felted when young. Flowers conspicuous, broadly funnelform to 

 campanulate, the tubes very short. Stamens numerous, short, borne in the throat of the 

 corolla, about one-third to one-half the length of the perianth-segments. Ovary and 

 flower-tube scaly, the scales naked in their axils. Fruit oblong, thick -walled and leathery, 

 usually dry at maturity and dehiscing by a large basal pore. Seeds black, pitted; embryo 

 curved. [From the Latin word, ferns, fierce, and cactus, referring to the heavy arma- 

 ment.] 



A genus of about 35 species, all from the southwestern United States and northern Mexico. Type species, 

 Echinocactus Wislizenii Engelm. 



Plants low, rarely over 2 dm. high; radial spines heavy; flowers greenish. 1. F. viridescens. 



Plants 0.5-3 m. high; some of the radial spines bristly or acicular; flowers yellow. 2. F. acanthodes. 



1. Ferocactus viridescens (Torr. & Gray) Britt. & Rose. San Diego Barrel 



Cactus. Fig. 3332. 



Echinocactus viridescens Torr. & Gray, Fl. N. Amer. 1 : 554. 1840. 

 Melocactus viridescens Nutt. in Teschemacher, Bost. Journ. Nat. Hist. 5: 293. 1845. 

 Echinocactus limitus Engelm. in J. M. Couit. Contr. U.S. Nat. Herb. 3: 374. 1896. 

 Ferocactus viridescens Britt. & Rose, Cactaceae 3: 140. pi. 14. 1922. 



Simple, rarely 1-2 branched at the base, globose or subglobose-depressed when young, be- 

 coming short-cylindric in age, 2.5-3.5 dm. in diameter, 3^ dm. high, usually broader than high; 

 ribs 10-20, rounded or obtusely angled, 1-2 cm. high, undulate. Areoles narrow, elliptic, 1-2 cm. 

 long, spinescent in the lower part, floriferous and felted in the upper part ; spines bright red to 

 brown or yellowish, central spines 4, stout, flattened and somewhat annulate, cruciately spreading, 

 the three upper about 2 cm. long, the lowest one stouter, 2.5-3.5 cm. long; radial spines 10-20, 

 spreading, 1-2 cm. long, acicular, but heavy; flowers greenish yellow, 3.5-4 cm. long; perianth- 

 segments oblong, serrulate on the margins, with reddish midveins ; scales on the ovary sub- 

 cordate, imbricate when young, distinct in age ; fruit 1 . 5-2 cm. long, yellowish green, or some- 

 times tinged with red; seeds about 1.5 mm. long, minutely pitted. 



Dry grassy hillsides near the sea coast. Upper Sonoran Zone; from vicinity of San Diego Bay, California, 

 southward about fifty miles near the sea in northern Lower California. March-May. 



