Description

Key Characters:

Growth Form: Highly specialized, usually succulent shrubs or small trees up to 4 m tall, often with a definite trunk, usually spiny, the spines variable in number, size, arrangement, and color, produced from specialized axillary structures (areoles).

Stems: Joints glossy green when fresh, narrowly obovate to oblong–lanceolate, the base somewhat cuneate, 10–35 cm long, 7.5–12.5 cm wide, margins undulate toward apex. areoles with 1–2(3) gray or yellowish to reddish brown spines with darker tips, 1–7.5 cm long, trunk areoles sometimes with 10 or more spines.

Roots:

Leaves: Leaves reduced, caducous. Blades subulate. Stipules absent.

Flowers: Flowers solitary. Flowers usually bisexual (perfect), diurnal, 7.5–10 cm long, 5–7.5 cm in diameter, very rarely unisexual, actinomorphic or occasionally zygomorphic. Outer perianth parts yellow with a reddish median stripe, 18–25 mm long, 12–15 mm wide, inner perianth parts yellow to orange, rotate, 25–40 mm long, 12–40 mm wide, distinct, gradually grading from sepaloid to petaloid, usually not sharply differentiated into 2 series; receptacle tube very short, naked or with scales and areoles bearing hairs, bristles, or spines. Stamens numerous, inserted in the throat of the receptacle tube, staminal filaments green to white. Ovary inferior, with areoles bearing hairs, glochids, and often spines; style green, 12–20 mm long; stigma lobes 8–10, cream yellow.

Fruit: Berries reddish purple; fleshy; conical to obovoid; 5–7.5 cm long; 4–5 cm in diameter; indehiscent. Seeds numerous; white to brown; flattened; enclosed in a hard; bony aril.

Ploidy: 2n = 22; 32; 33

Habitat:

Elevation Range: