144 CACTACE^. (cactus FAMILY.) 



ones pinnatifid ; fruit slightly roughened. — Ponds and ditches, Florida, and 

 northward. July. 



4. M. scabratum, Michx. Stem short (6'- 12') ; leaves4-5 in a whorl, 

 the divisions few and capillary, the floral ones linear, pectinately toothed ; fruit 

 strongly ridged and roughened. — Shallow ponds. South Carolina, and north- 

 ward. June and July. 



Order 56. CACTACKiE. (Cactus Family.) 



Succulent, §hrubby, and commonly leafless and prickly plants, with 

 globular, or co'umnar and an<rular, or flattened and jointed stems, and 

 solitary sessile flowers. — Sepals and petals similar, imbricated in several 

 rows, and adherent to the 1-celled ovary. Stamens indefinite, with long 

 filaments, inserted on the base of the petals. Style single : stigmas nu- 

 merous. Fruit baccate. Seeds numerous, campylotropous, borne on 

 several parietal placenta. Albumen scanty or none. 



1. CEREUS, IIuw. 



Sepals and petals united into an elongated tube .ibove the ovary. Stamens 

 inserted on the tube. Style filiform. Stigma many-lobed. Seeds without al- 

 bumen. — Stems elongated, ribbed or angled ; the anglgs bearing tufts of spines 

 and showy flowers. 



1. C. monoclonos, DC f Stem tall, columnar, 6-8-angled, green; 

 angles obtuse; spines short, brownish. — Key West. — Stem 4° -10° higli. 

 Flowers 6' long, the inner petals lanceolate, acuminate, white; the outer ones 

 linear, greenish, and gradually diminishing into the scales of the tube. Stigmas 

 10 or more, filiform, cxserted. Stamens included. 



2. C. triangularis. Haw. f Stem elongated, jointed, 3-sided, rooting at 

 the joints; flowers greenish externally, white within, very large; fruit large, 

 naked. — Key West. — Stem climbing over bushes. Joints 1° long. 



2. OPUNTIA, Tourn. Prickly Pear. 



Sepals and petals not united into a tube. Stamens inserted into the base of 

 the petals. Style cylindrical. Stigma 3-8-lobed. Seeds with thin albumen. 

 — Stems with flat or rarely cylindrical joints. Leaves fleshy, with tufts of bristly 

 liairs and commonly strong spines in their axils, deciduous. Flowei-s large, 

 yellow. 



1. O. Ficus-IndicUS, Haw. Stem erect, spreading ; joints oval and 

 obovate ; leaves subulate, bristly in the axils, without spines ; fruit bristly, ob- 

 ovate, red within, edible. — South Florida. May. — Joints 1° long. 



2. O. vulgaris, Mill. Stem prostrate; joints obovate, pale; spines few 

 and short ; fruit nearly smooth. — Dry sandy soil, Florida and northward, near 

 the coast. June and July. 



