Common Name: CACTUS FAMILY
Habit: Perennial herb, shrub, tree, generally fleshy. Stem: cylindric to spheric, or flat; surface smooth, tubercled, or ribbed (grooved); nodal areoles bearing flowers. Leaf: generally 0 or early-deciduous, flat to +- cylindric. Spines: areoles generally with central, radial spines, occasionally with glochids. Flower: generally 1 per areole, bisexual [unisexual], sessile, radial [bilateral]; perianth parts generally many [5], scale-like to petal-like; stamens many; ovary inferior [superior], style 1, stigma lobes generally several [many]. Fruit: dry to fleshy or juicy, indehiscent to variously dehiscent, spiny, scaly, or naked; tubercled or smooth. Seed: generally many, occasionally 0--few.
Genera In Family: +- 125 genera, +- 1800 species: America (especially deserts), Africa; many cultivated, some edible. Note: Spines smaller, fewer (0) in shade forms; yellow spines blacken in age. Introduced species increasingly escape cultivation. Hybridization common in some genera.
eFlora Treatment Author: Bruce D. Parfitt, except as noted
Scientific Editor: Bruce D. Parfitt, Douglas H. Goldman, Bruce G. Baldwin, Thomas J. Rosatti.

Common Name: PRICKLY-PEAR
Habit: Shrub, tree; roots fibrous [tuberous]. Stem: generally erect, < 6 [12] m; segments generally flat (+- cylindric), generally firmly attached; tubercles 0 to +- developed; ribs 0. Leaf: small, conic, fleshy, deciduous, present on young stems, ovaries. Spines: 0--many per areole, cylindric or flat, tip smooth or barbed, epidermis persistent; glochids generally many. Fruit: juicy, fleshy or dry; wall thick, bearing areoles; spiny or not. Seed: in a bony, +- white aril.
Etymology: (Possibly from Papago name ("opun") for this food pl; or for a spiny plant of Opus, Greece) Note: Spines smaller, fewer in shade forms; yellow spines blacken in age. Spineless stems, ovaries, and fruit generally with glochids, these occasionally long, conspicuous; hybridization common. Taxa with cylindric to club-shaped stems moved to Cylindropuntia, Grusonia.
eFlora Treatment Author: Marc Baker, Lucas C. Majure & Bruce D. Parfitt

Habit: Shrub. Stem: 7--40 cm, branches sprawling to ascending or erect; segments 5--21 cm, green to +- blue, generally papillate-puberulent. Spines: generally 0(8) per areole, glochids many. Flower: inner perianth +- 4 cm, pink-magenta; filaments deep magenta-red; style white or pink, stigma white. Fruit: 2--4 cm, dry in age, green and purple becoming tan, generally puberulent; areoles 24--76. Seed: 6.5--9 mm, +- spheric.