DICOTYLEDONOUS PLANTS 155 
when ripe, eatable. Dry rocks and sandy ground, from Massachu- 
setts south along the coast. 
2. O. Rafinesquii, Engelm. Prostrate, green. Leaves 4-4 in. long, 
awl-shaped, spreading; bristles often intermixed with a few small 
spines and a larger one 3-1 in. long. Flowers larger than in No. 1 
and with 10-12 petals. Fruit about 11 in. long, much tapered at 
the base. In poor soil. ; 
_ 3. 0. missouriensis, DC. Prostrate, light green. Leaves very 
small, with bristles and 5-10 spines in their axils. Flowers 2-3 in. 
in diameter. Fruit dry and spiny. Wisconsin, S. and W. 
Il. PHYLLOCACTUS, Link. 
Stems cylindrical when old, with long, flattened, fleshy but | 
leaf-like, sinuate or serrate branches. Flowers nearly or quite 
regular, from the notches in the margins of the joints. 
1. P. Ackermanni, L. Flowers very showy, bright red. Perianth- 
tube shorter than the petals. Sepals scattered, small and bract-like. 
Petals many, 2-3 in. long, widely spreading, somewhat channeled, 
sharp-pointed. Cultivated from Mexico. 
Ill. CEREUS, DC. 
Stem more or less prismatic but strongly ridged, with bun- 
dles of spines borne on the ridges, sometimes prostrate or 
trailing, sometimes erect, columnar, and 50 or 60 ft. high. 
Flowers usually showy, borne on the sides of the stem, gener- 
ally with a rather long perianth-tube, which is covered outside 
with scale-like sepals, usually with tufts of wool in their axils. 
‘Petals many, mostly long and spreading. 
1. C. speciocissimus, DC. Stems 2-3 ft. high, with 3-4 broad- 
winged and sinuate ridges. Flowers open in-the daytime and lasting 
several days, red or crimson, very showy. Petals longer than the 
tube, stamens white, drooping, very numerous. Commonly culti- 
vated from Mexico. 
2. C. grandiflorus, Mill. NiGcuHt-BsLoomine Cereus. Stems long, 
climbing by aerial roots, nearly cylindrical, but with 5 or more blunt 
angles. Flowers very showy, opening only for one night, wilting 
early in the morning, extremely fragrant. Sepals dull yellow. Petals 
pearly white, spreading, 6-8 in. long. Cultivated from Mexico. 
