CACTACE. 
SILVA OF NORTH AMERICA. dl 
CEREUS. 
LOWERS perfect ; calyx elongated, the lobes numerous, imbricated in many series ; 
petals numerous, imbricated in estivation ; stamens indefinite, inserted in the tube of 
the calyx ; ovary inferior, 1-celled, many-ovuled. Fruit baccate, many-seeded. 
Cereus, Haworth, Syn. Pl. Suce. 178 (1812). — Meisner, 
Gen. 128. — Endlicher, Gen. 944.— Miquel, Bull. Sct. 
Phys. et Nat. Néerl. 1839, 110. — Bentham & Hooker, 
Gen. i. 849. — Baillon, Hist. Pl. ix. 31. 
Echinopsis, Zuccarini, Abhund. Ahud. Miinch. ii. 675 
(1837). — Miquel, Bull. Sci. Phys. et Nat. Néerl. 1839, 
109. 
Cephalocereus, Pfeiffer, Otto «: Dietrich Gartenz. 142 
(1838). 
Cephalophorus, Lemaire, Cact. Hort. Monvill. 33 (1838). 
Pilocereus, Lemaire, Cact. Gen. et Spec. Nov. 7 (1839). 
Echinonyctanthus, Lemaire, Cact. Gen. et Spec. Nov. 10 
(1839). 
Echinocereus, Engelmann, Wislizenus Memoir of a Tour 
to Northern Mexico (Senate Dov. Bot. Appx.), 91 (1848). 
Spiny leafless trees or shrubs, with copious watery juice, the stems sometimes columnar and six to 
twenty-ribbed, sometimes cylindrical, erect and slightly many-ribbed, sometimes remotely jointed, more 
or less three to seven-angled and spreading or climbing, sometimes cylindrical, weak, remotely jointed 
and eight to twelve-ribbed, and sometimes short, globular or oblong, many-ribbed, and clustered or 
branched from the base. Buds on the back of the ridges, sprmging from the axils of latent leaves, 
geminate, superposed, the upper producing a branch or flower, the lower arrested and developed into a 
cluster of spines surrounded by an elevated cushion or areola of chaffy tomentose scales. Flowers 
lateral, diurnal or nocturnal, large and showy, often fragrant. Lobes of the calyx spirally imbricated 
in many ranks, forming a long and slender or short or subglobose nectariferous tube, those of the 
exterior ranks adnate to the ovary, scale-like, only their tips free with a tuft of hairs and sometimes a 
cluster of spines in their axils, those of the terior ranks free, elongated, green, yellow, or bright- 
colored. Petals cohering by their bases with the top of the calyx-tube, larger than its interior lobes, 
spreading, recurved, white, red, or crimson. Stamens numerous, in two or many ranks; filaments 
filiform, adnate by the base to the tube of the calyx, those of the interior ranks free, the exterior united 
into a tube; anthers oblong, minute, attached on the back below the middle, introrse, two-celled, the 
cells opening longitudinally. Ovary inferior, one-celled; style elongated, filiform, terminal, divided 
into numerous radiating linear branches stigmatic on the inner face; ovules indefinite, horizontal, 
anatropous, inserted on numerous parietal placentz ; funiculi long and slender, becoming thick and 
juicy in the fruit. Fruit baccate, squamate, or spinescent, many-seeded, often edible. Seeds destitute 
of albumen, subglobose and tuberculate, or obovate smooth or pitted. Embryo straight; cotyledons 
abbreviated or foliaceous, usually hamate ; radicle conical, turned towards the hilum.! 
1 The following sections of the genus are now usually recog- 
nized : — 
EcHINOCEREvS. Stems short, usually subglobose, branched from 
the base ; calyx-tube abbreviated, subcampanulate ; ovary acule- 
ate ; stigmas green ; seed tuberculate ; cotyledons suberect. 
Eucrrevs. Stems long ; calyx-tube elongated, usually furnished 
with slender hair-like spines ; stigmas pale ; seed smooth or rarely 
rugose ; embryo hooked at the apex. 
LEPIpocEREvs. Stems elongated ; calyx-tybe short, many-lobed, 
covered like the fruit with scales ; seeds smooth ; embryo hooked 
at the apex. 
Pitocergvus. Stems elongated ; calyx-tube short, few-lobed, cov- 
ered with scales ; stigmas pale ; seed smooth ; embryo hooked at 
the apex. 
Ecuinopsis. Stem depressed, ribbed, globose or cylindrical ; 
calyx-tube elongated, pulvilligerous, many-lobed ; ovaries bristly, 
covered with scales ; cotyledons small, connate. 
