ECHINOCEREUS 



ECHINOCEREUS 



1095 



HH. Tube of fl. and spines of ovary short and stout, the 

 surrounding hairs short. 

 i. Central spines several. 



18. pectinatus, Engelm. (Cereus pectinatus, Engelm.). 

 Clustered sts. cylindrical or ovoid, reaching a height 

 of 10 in. by 3 in. diam.: ribs 13-23, straight: radial 

 spines 16-30, pectinate, horizontally spreading and 

 appressed, straight or curved, the laterals longest, 

 round, hardly ^in. long; central usually absent, or as 

 many as 5, which are short, conical and superposed, 

 white, with tips and bases variously colored with pink, 

 yellow or brown; later all beeome gray: fls. lateral, from 

 near the crown, 2^-4 in. long; ovary tuberculate and 

 spiny, light to dark rose-red or rarely white: fr. globose, 

 spiny, green to reddish green. Mex. 



Var. adustus, K. Sch. (Cereus adustus, Engelm.). 

 Like the type, but with black-brown to chestnut-brown 

 spines. Mex. 



Var. rufispinus, K. Sch. Of more robust growth: 

 radial spines curved, red. Mex. 



ii. Central spines none. 



19. rigidissimus, Engelm. (Cereus cdndicans, Hort. 

 C. rigidissimus, Hort.). RAINBOW CACTUS. Fig. 1376. 

 Sts. comparatively shorter and thicker: radial spines 

 16-20, coarser and stiff er, straight or very little curved; 

 base thickened, white, yellow or red to brown, these 

 colors commonly arranged in alternating bands around 

 the plant, the spines of adjacent clusters interlock- 

 ing; centrals absent. Ariz, and N. Mex. 



DD. Spines not pectinate. 



E. Ribs 10 or fewer. 



F. Fls. crimson. 



20. mojavensis, Rtimpl. (Cereus mojavensis, Engelm. 

 & Bigel.). Sts. clustered, ovoid, reaching 3 in. height 

 by 2 in. diam.: ribs 8-12, conspicuously undulate: 

 radial spines 5-8, the lowest pair the longest, reaching 

 about 2J4 m - long; all are white with brown tips, 

 subulate, straight or curved, strongly bulbose at the 

 base; central solitary, or sometimes absent, stronger 

 and somewhat longer and darker colored; later all the 

 spines become gray: fls. 2-3 in. long, deep carmine: 

 fr. ellipsoidal, about 1 in. long. Deserts of Ariz., Nev. 

 and Calif. 



FF. Fls. purple-violet. 



G. The spines dark, often of several colors. 



H. Central spine i. 



21. Fendleri, Riimpl. (Cereus Fendleri, Engelm.). 

 Irregularly clustered: st. cylindrical or rarely ovoid 

 or even globose, sparingly branching, 3-7 in. high by 

 1/4-2 K in. diam.: ribs 9-12, straight or slightly spiral, 

 undulate: radial spines 7-10, subulate, straight or 

 curved, the lowest or the 2 lower laterals the longest, 

 about 1 in., stronger, quadrangular, white; the 2 next 

 higher brownish; the upper ones round, white and much 

 shorter; all are bulbose at the base; central solitary 

 (or in old plants 3-4), very strongly thickened at the 

 base, round, black, sometimes with a lighter colored 

 tip, curved upward, reaching a length of 1% hi.: 

 fls. lateral, from near the crown, 2-3^ in. long, dark 

 carmine-red to purple and violet: fr. ellipsoidal, spiny, 

 green to purple-red, about 1 in. long. Colo., Utah and 

 south to N. Mex. B.M. 6533. 



HH. Central spines several. 



22. Engelmannii, Lem. (Cereus Engelmannii, Parry). 

 Sts. clustered, cylindrical to ovoid, 4-10 in. high, 1%- 

 2K in- diam., light green: ribs 11-13, undulate: radial 

 spines 11-13, somewhat angled, stiff, sharp, straight or 

 somewhat curved, horizontally spreading, the lowest or 

 lower laterals the longest, about J^in., the upper ones 

 the shortest, whitish with brown tips; centrals 4, stiff, 

 straight, angled, stout, the lowest one deflexed, white 



1376. Echinocereus rigidissimus. 



to dark-colored, reaching a length of 2^ in., the upper 

 ones about half as long, spreading, brown : fls. lateral, 

 from just below the crown, l%-2 J^in. long, purple- 

 red: fr. ovoid, green to purple-red, spiny, later naked, 

 about 1 in. diam. ; pulp purple-red. Calif, to Utah and 

 south into Mex. 



Var. chrysocentrus, Engelm. & Bigel. The 3 upper 

 centrals golden yellow, the lowest white. Mojave Des- 

 ert, Calif. 



Var. variegatus, Engelm. & 

 Bigel. The 3 upper centrals 

 curved, horn-colored and mottled 

 with black. Utah, Nev. and Calif. 



GG. The spines usually white or 



straw-colored. 

 H. Central spines somewhat curved. 



23. dfcbius, Riimpl. 

 (Cereus dubius, En- 

 gelm.). Tolerably 

 thickly clustered: sts. 

 branching at the 

 base, cylindrical or 

 elongated ellipsoidal, 

 4/^-7 in. high by 

 1J^-2J^ in. diam.: 

 ribs 7-9, undulate: 

 areoles iHhiHj in. 

 apart, round, covered 

 with short curly 

 white wool, later 

 naked : radials 5-8, 

 subulate, horizon- 

 tally spreading, stiff, 



round or faintly angled, the lower ones usually the 

 longest, about 1 in. long, the upper ones about half 

 as long, or sometimes absent, transparent white; cen- 

 trals 1-4, stronger and longer, bulbose at the base, 

 straight or curved, reaches 2^ in. length, the lowest 

 one longest, straight, porrect or deflexed, the upper 

 ones spreading: fls. lateral, 2 in. long, rose-red to violet: 

 fr. spherical, greenish to purple-red, covered with 

 bundles of deciduous spines. Texas and N. Mex. 



HH. Central spines straight. 

 I. Sts. erect, with the spines pale at base. 



24. enneacanthus, Engelm. (Cereus enneacdnthus, 

 Engelm.). Freely branching at the base of the st. and 

 thus forming thick, irregular clusters: branches ascend- 

 ing, usually 3-5 in. long by 1^-2 in. diam., green or 

 sometimes reddish: ribs 8-10, straight, often divided 

 by transverse grooves into more or less conspicuous 

 tubercles: areoles ^-^gin. apart, round, white curly- 

 woolly, soon naked: radial spines 7-12 (mostly 8), 

 horizontally spreading, needle-form, straight, stiff, 

 translucent white, base bulbose, the under one longest, 

 reaching ab9ut Kin., the upper one very short; cen- 

 tral solitary, or seldom with 2 additional upper ones, 

 straight, porrect or deflexed, round or angled, whitish 

 to straw-yellow or darker, H~1M in. long; later all the 

 spines are gray: fls. lateral, from near the crown or 

 lower, l%-2 1^ in. long, red to purplish: fr. spherical, 

 green to red, spiny, %-l in. long. Texas and N. Mex. 



n. Sts. spreading and flabby, with the spines red at base. 



25. Merkeri, Hildmann. Sts. at first upright, columnar, 

 later reclining and by branching at the base forming 

 clusters, in new growth bright green, later gray to 

 gray-brown and corky: ribs 5-9, undulate to more or 

 less tuberculate: areoles %in. and more apart, round, 

 white velvety, later naked: radial spines 6-9, the 

 upper ones the longest, reaching 1J^ in. length, some- 

 what confluent with the centrals, subulate, spreading, 

 straight; centrals 1-2, stronger, reaching a length of 2 

 in.; all the spines are white, nearly transparent, with 

 red-tinted bulbose base. N. Mex. 



