DESCRIPTIONS AND ILLUSTRATIONS OF PLANTS OF THE 



CACTUS FAMILY. 

 Tribe 3. CEREEAE. 



Plants more or less fleshy, terrestrial or epiphytic, simple and i -jointed or much branched 

 and many-jointed, the joints globular, oblong, cylindric, columnar or flattened, and winged or 

 leaf -like, often strongly ribbed, angled, or tubercled; leaves* usually wanting on the joints (in a 

 few cases developing as scales) but usually developing as scales on the ovary or perianth-tube ; are- 

 oles never producing glochids ; spines usually present (rare or wanting in most epiphytic genera and 

 in a few species of other genera), various in color, structure, arrangement, and size, never sheathed; 

 flowers sessile, mostly with a definite tube, various in size and shape in different genera, usually 

 solitary at areoles, opening at various times of the day; perianth campanulate, funnelform or rotate; 

 fruit usually a fleshy berry, but sometimes dry and dehiscing by a basal pore (in i species by an 

 operculum); seeds usually small, brown or black, with a thin, more or less brittle testa; cotyledons 

 usually minute knobs. 



This tribe contains most of the genera and three-fourths or more of the species of 

 Cactaceae. It has a wider range in structure of stems and flowers than is exhibited by the 

 other tribes, the species being grouped in many genera. The first two subtribes are 

 treated in this volume. 



KEY TO SUBTRIBES. 



Perianth funnelform, salverform, tubular, or campanulate; segments several or many. 



Areoles mostly spine-bearing; joints ribbed, angled, or tubercled, very rarely flat; mostly 



terrestrial cacti. 

 Flowers and spines borne at the same areoles. 



Several-jointed to many-jointed cacti, the joints long. 



Erect, bushy, arching, or diffuse cacti i . Cereanae 



Vine-like cacti, with aerial roots 2. H\locereanae 



One-jointed or few-jointed cacti, the joints usually short, sometimes clustered, ribbed, 

 or rarely tubercled. 



Flowers at lateral areoles 3. Echinocereanae 



Flowers at central areoles (See Gymnocalycium) 4. Echinocactanae 



Flowets and spines borne at different areoles; short, one-jointed cacti. 



Flowering areoles forming a central terminal cephalium 5. Caclanae 



Flowering areoles at the bases or on the sides of the tubercles 6. Coryphanthanae 



Areoles mostly spineless; joints many, long, flat; perianth mostly funnelform; epiphytic cacti .7. Epiphvllanae 

 Perianth rotate, or nearly so; segments few; mostly spineless, epiphytic, slender, many- jointed cacti. 8. Rhipsalidanae 



Subtribe i. CEREANAE. 



Erect, bushy or sometimes diffuse, stout or slender cacti, the stems and branches several- 

 jointed to many-jointed, usually very spiny, none epiphytic but species of 2 or 3 genera giving off a 

 few roots when the branches touch the ground; flowers i or rarely several from the upper part 

 of old areoles; in some genera the flowering areoles and their spines greatly modified; flowers 

 either diurnal or nocturnal, various in size, color, and shape; stamens numerous, borne on the 

 flower-tube; fruit smooth or spiny, usually fleshy, often edible; seeds various. 



We group the species known to us in 38 genera. 



KEY TO GENERA. 



A. Flowers solitary at the areoles, mostly large. 



B. Perianth funnelform, salverform, pyriform, or campanulate; limb relatively large. 

 C. Ovary naked, or rarely bearing a few scales, which sometimes subtend tufts 



of short hairs. 

 Perianth funnelform, elongated. 



Columnar cacti, or with columnar branches; perianth falling away by 



abscission i. Cereus (p. 3) 



Slender, elongated cacti; perianth withering-persistent 2. Momiillea (p. 21) 



Perianth short-campanulate or short-funnelform to pyriform; columnar 



cacti 3. Cephalocereus (p. 25) 



*Plants of the tribe Cereeae are usually said to be without leaves. Ganong, however, reports leaves in Cactus, 

 Echinocactus, and Cereus, but we have never seen leaves on any plants of Cereus proper. However, they are 

 easily observed on young growth of various species of Harrisia, Acanthocereus, Nyctocereus, Selenicereus, Hylocereus, 

 and some other genera. 



i 



