(closed Cactus, referring doubtless to the peculiar flowers). Cactaceae. Slender columnar cacti, with few branches and many-ribbed: flowers short and narrowly curved, orange-red; ovary covered with small appressed bracts bearing hairs in their axils; filaments somewhat exserted and grouped together near the upper lip: fruit spineless; pulp white; seeds slightly punctate. - About 14 species have been described in this genus.

Baumannii, Lem. (Cereus Baumannii, Lem. C. colubrinus, Otto). stems dark green, slender, flexuose, columnar, reaching a height of 6 ft. and a diam. of 1-1 1/2 in., the few branches ascending, slender, parallel with the main stem: ribs 12-16, rounded: areoles close together, brown: spines fine, slender, very sharp, 15-20, fascicled, white to yellow or dark brown, about 1/4in. long; sometimes a single one from the center reaches a length of 3/4in.: flowers numerous, tubular, zygomorphous, 2 1/2-3 in. long by about 1/2in. diam. throughout, red or sometimes with orange-red petals and red tube. Uruguay, Paraguay and Argentina. j. n. Rose.