DESCRIPTIONS AND ILLUSTRATIONS OF PLANTS OF THE 

 CACTUS FAMILY. 



Tribe 3. CEREEAE. 

 Subtribe 6. CORYPHANTHANAE. 



Terrestrial, spiny, low cacti, mostly globose, sometimes cylindric, rarely elongated, i-iointed, 

 solitary or cespitose, tuberculate, the tubercles numerous ; tubercles usually arranged in spirals ; juice 

 watery or milky; flowers always solitary at areoles, either at top or side of plant, but never at spine- 

 areoles, large or small, regular (except in the genus Cochemiea) ; ovary naked or bearing a few scales ; 

 fruit a green or red indehiscent berry (except in the genus Bartschella) ; seeds small, brown or black. 



We recognize 14 genera. 



Key to Genera. 



A. Ovary more or less scaly (not known in MamiUopsis). 

 Flower campanulate with short tube. 



Some of spines hooked i. Ancistrocactus (p. 3) 



None of spines hooked (see species No. 2 in Neolloydia). 



Tubercles not deeply grooved ; fruit scaly 2. Thelocactus (p. 6) 



Tubercles deeply grooved; fruit nearly naked 3. Neolloydia (p. 14) 



Flower-tube elongated, scaly 4. MamiUopsis (p. 19) 



AA. Ovary naked or nearly so. 



B. Flowers irregular 5. Cochemiea (p. 2 1) 



BB. Flowers regular. 



C. Flowers central, borne in axils of young, usually nascent, tubercles, large 

 (except in genus No. 8); tubercles containing a watery juice; fruit dull 

 green or red; seeds brown or black. 

 D. Tubercles grooved on upper side; flowers borne at base of groove. 



Seeds mostly light brown; fruit greenish or yellowish even when 



mature, ripening slowly 6. Coryphantha (. 23) 



Seeds black to dark brown; fruit red, maturing rapidly. 



Tubercles long, not numerous, not persisting as woody knobs; aril 



of seed large 7. Neobesseya (p. 51) 



Tubercles short, numerous, persisting after spines fall off as woody 



knobs; aril of seed small 8. Escobaria (p. 53) 



DD. Tubercles not grooved above. 



Fruit circumscissile; tubercles fleshy; spines acicular 9. Bartschella (p. 57) 



Fruit not circumscissile; tubercles woody; spines pectinate 10. Pelecyphora (p. 59) 



CC. Flowers lateral, borne in axils of old and mature tubercles; these never 

 grooved above. 



Seeds with a large corky aril 11. Phellosperma (p. 60) 



Seeds without a corky aril. 



Flowers large with an elongated tube; tubercles elongated, flabby. .. . 12. Dolichothele (p. 61) 

 Flowers small, campanulate; tubercles not flabby. 



Hilum of seed large; tubercles lactiferous; spines pectinate 13. Solisia (p. 64) 



Hilum of seed minute; tubercles sometimes lactiferous, but not in 



species with black seeds; spines not pectinate 14. Neomammillaria (p. 65) 



1. ANCISTROCACTUS gen. nov. 



Small, globular or short-cylindric plants, indistinctly ribbed, strongly tubercled, very spiny, 

 one of central spines always hooked ; flowering tubercles more or less grooved on upper side ; flowers 

 rather small, short, funnelform, borne at top of plant; ovary small, bearing a few thin scales, these 

 always naked in their axils; fruit oblong, greenish, juicy, thin- walled, usually naked below but with 

 a few broad cordate, thin-margined scales above; seeds globular, rather large, brownish to black, 

 the papillae low, flattened ; hilum large, depressed, sub-basal, surrounded by a thick rim. 



Type species: Echinocactus megarhizus Rose. 



Engelmann in describing Echinocactus scheeri, one of the species of this genus, refers 

 to its anomalous characters when he says : 



"Seeds are large, about i line long, 0.8 line in diameter, with very minute and flattened tuber- 

 cles, broum (the only Echinocactus with seeds of that color known to me) ; hilum large and circular, 

 surrounded by a thick rim; albumen very small; embryo curved but cotyledons small, connate, more 

 like those of a Mammillaria, separating on the curvature and not at the end of the hook, as in all 

 other hooked embryos of Cactaceae known to me." (Cact. Mex. Bound. 19. 1859.) 



