Shrubs or small trees, erect, to 2 m, often with short trunk, usually oval in cross section. Stem segments firm. Flowering spring-summer (Feb-Aug). Sand dunes, scrub woodland flats; 0-60 m; Fla. Opuntia humifusa var. ammophila is poorly known and needs additional ecologic, taxonomic, and molecular study. The distribution given follows L. D. Benson (1982).