by 3-5 in. in diam.), branches 

 columnar : ribs mostly 7, sel 

 dom 8-9, thick, slightly undu 

 late, obtuse and with couvtx 

 faces, about 1 in. high, bluish 

 green, frequently having a de 

 pressed line near the areolfe 

 areolae about Kin. apart, large 

 gray: radial spines ()-9, radi 

 ate or spreading, strong, sub 

 ulate, %m. long, horn cokr 

 later black ; central spines 

 1-3, somewhat stronger an I 

 longer than the radials, more 

 or less conspicuously porreet 

 fls. from the lateral areolfe 

 near the end of the branches 

 2K-3 in. long, tolerably fleshy 

 white : fr. depressed-globose 

 2 in. in diam. by little more 

 than 1 in. long. Brazil. 



C. PScten - aborlginum 

 Wats., is closely allied to the 

 above. It is Sonoran, but n t 

 known to be in cult. G. F 

 7:335. 



19. ebiirneus, Salm-Dyck 

 (C. prttinosus , Otto. C 4du 

 Zis, Hort. ). Stem simple and 

 glaucous, with 7-10 ribs 

 spines subulate, rigid, ivor\ 

 white, with black tip (purplish when young) 

 radials 8-10, central usuall) solitary (some 

 times 3-4): fls. purplish. W Ind Mex ^ 

 Cent Amer., S. Amer. 



20. geom6trlzans,Mart. (C pugjoHffriKs Lem ) Sim 

 pie, 4 in. in diam., with 5-9 obtuse ribs with broad in 

 tervals : spines 3-6, unequal, stout and blackish, the 

 solitary central one (sometimes wanting) very long and 

 stout : fls. pinkish white, about 1 in. long and 2 in. broad. 

 Mexico. 



21. Cdchal, Orcutt. Stout at base, and repeatedly 

 forking above, becoming 4-10 ft. high: rihs 4-8, obtuse, 

 with wide, shallow intervals : spines few and stout, the 

 solitary central one stoutest: fls. purplish green, 1-1' _ 

 in. long : fr. the size and shape of an olive, not spiny, 

 red (frequently grayish or yellowish brown) . L. Calif.— 

 The short and stout woody trunk is often 1ft. in diam., 

 the long branches 2-8 in. in diam. 



CO. Bihs of stem strongly compressed tatcrallij. 



22. Peruvianus, Haw. {C monoclonos, DC). Hedge 

 Cactus. Tall, 30-50 ft., branching freely toward the 

 base, columnar, 4-8 in. in diam. , new growth dark green 

 and glaucous, becoming a dull green with age, and, in 

 old stems, becoming corky: ribs 5-8, compressed : are- 

 ola %-i in. apart, in new growth covered with con- 

 spicuous, curly brown wool, becoming gray : radial spines 

 about 6-7, about %-% in. long ; central solitary, reach- 

 ing a length of 2K in. ; the number of spines increases 

 with age to as many as 20. all are rigid, brown : fls. 

 abundant, from the lower part of the stem, white, noc- 

 turnal, 6-7 in. long by 5 in. in diam. Fla., W. Ind., Mex. 

 and S. Amer. G.C. Ill, 24: 175 (var. monstrosus). 



Var. Alacriportinus, K. Sch. (C. Alacriport&mis, 

 Mart. ). Of somewhat weaker growth, low, and less con- 

 spicuously pruinose in the new growth, which is con- 

 sequently nearly clear green. S. Brazil. 



23. Jamaciru, Salm Dvck (C. vdliclus. Haw.). Stems 

 upriglit, robust, ri-i.l, 1_'-16 ft. high by as much as 6 in. 

 in diam. ; youii;^ ;^ni\vtli azure-blue, turning dark green 

 with age, glaueou.s: ribs 4-6, thin, compressed, crenate: 

 radial spines 5-7, stiff, needle-like, clear yellow with 

 brown points, or brown and finally black, about '.f-'J^in. 

 long; centrals 2-4, somewhat stronger, porreet. %-3 in. 

 long: fls. large, 10 in. long by 8 in. in diam., white noc- 

 turnal. Braz., Venezuela. 



24. oandeUbrum, Weber (C Belieuli, Hort.). Tall, 

 columnar, simple or branching only at the base, dark 

 green with a faint trace of blue, 30 ft. high by 4 in. in 

 diam. : ribs 9, blunt, strongly compressed, %\n, high, 

 slightly crenate : areolae 1-2 in. apart, ovate, large. 



white: radial spines mostly 9, the under ones longest 

 and about an inch long, laterally compressed, the upper 

 ones shorter, round, all bulbose and black at the base, 

 ivory-white above ; central solitary, very large, 3^ in. 

 long, dagger-like, laterally compressed and faintly an- 

 gled, porreet, ivory-white to gray, base black and 

 strongly bulbose : fls. from the lateral areolse, 3-1 in. 

 long, white: fr. the size of a small orange, covered with 

 small scales, in the axils of which are wool and bristles 

 Mexico. 



25. chalybaeus, Otto. Stems upright, branching above, 

 arborescent, azure blue and pruinose, later dark grsen, 

 lK-4 in. in diam.: ribs 6, in young growth very much 

 compressed, later depressed till the stem is nearly cy- 

 lindrical : areolae about %in. apart, dark gray-brown ; 

 radial spines mostly 7, about Kin. long; centrals .3-4, 

 similar but somewhat stronger and a little longer ; all 

 the spines are pointed, stiff, when young are black, 

 later brown to gray with black tips, bulbose at the base : 

 fls. very similar to those of C. ccp^rulescens. Argentine 

 Republic. 



AA. Stems erect, less than 2 in. in diam. 

 B. Sibs of stem 10 or more. 



26. serpentinus, DC. Stems columnar, tall, slender, 

 flexuose, 5-8 ft. high by l-l'4in. in diam., tapering at 

 the point : ribs 10-13, low, obtuse : areolse about ^in. 

 apart: radial spines 10-12, slender, needle form, stiff, %in. 

 long ; centrals 1^, pink and white when young, later 

 gray; the number of spines increases by new ones ap- 

 pearing later : fls. from the upper lateral areola*, slen- 

 der, green, spiny tube with funnel-shaped corolla, about 

 6 in. long by 3 in. in diam., white, nocturnal: fr. ovoid, 

 red, covered with deciduous spines. Cent. Mex. B.M. 

 350G. 



27. Badmannil, Lem. (C. eoliibrtnits. Otto). Steins 

 dark green, slender, flexuose. columnar, reachingaheight 

 of 6 ft. and a diam. of I-IV2 in., the few branches ascend- 



