144 CACTACK/K. (cactus FAMILY.) 



ones piimatifid ; fruit slightly rouylicncd. — Ponds and ditches, Florida, and 

 northward. July. 



4. M. scabratum, Michx. Stem short (6'- 12'); leaves 4- 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. 



Ordku 06. CACTACEiE. (Cactus Family.) 



Succulent, shrubby, and commonly leafless and prickly plants, with 

 globular, or co!umnar and angular, 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, canipylotropous, borne on 

 several parietal placentae. Albumen scanty or none. 



1. CEREUS, Haw. 



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

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

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

 and showy flowers. 



1. C, monoclonos, DC? Stem tall, columnar, G-8-angled, green; 

 angles ol)tus'j; sj)incs sliort, bro^vnisll. — Key West. — Stem 4"- 10° high. 

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

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

 10 or more, filiform, exscrted. Stamens included. • 



2. C. triangularis, Ilaw. ? Stem elongated, jointed, .3-sided, rooting nt 

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

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



2. OPUITTIA, Tourn. ruiCKLY Fear. 



Sepals and petals not imited 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 flesliy, with Infts of bristly 

 hairs and commonly strong spines in their axils, deciduous. Flowers large, 

 yellow. 



1. O. FiCUS-IndicUS, Haw. Stem erect, sjjrcading ; joiiUs oval and 

 obovatc; leaves subulate, bristly in the axils, witliout Pj>ines ; fruit bristly, ob- 

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



2. O. vulgaris, Jlill. Stem i)r()strate; joints ot)ovafe, pal(> ; s[)iiies few 

 and short; fruit nearly sinooili. — Dry sandy soil, I'loriila ami northward, near 

 the coast. June and July. 



