Xerophyte

Habit

It is a fiercely spiny cactus that develops into a shrub or small tree.

Areoles and Spines

Areoles large whitish, 2 cm apart. Spines ivory, stout, at least when young, greyish later; 1 to 4 centrals, porrect, 5-7 cm (or even 12 or more cm long) 8 to 12 radials, up to 4 cm long.

Sun Exposure

Outside full sun or afternoon shade, inside needs bright light, and some direct sun.

Flowers

Flowers open during the day, white, 14 cm long, outer perianth-segments white but tinged with red or brown; inner perianth-segments white, acuminate.

Ribs

10 to 17 low and broad, separated by narrow intervals, divided into large tubercles even when fully mature.

Stem

Rarely single, usually of several branches, sometimes of many, arising from near the base, starting nearly at right angles to the main trunk but soon erect, up to 8 m tall, stems 10-12 cm in diameter.