nightblooming cereus, more...
Shrubs, erect to sprawling, usually inconspicuous. Roots turnip-shaped, usually 15-30 × 5-12 cm (much larger ones known). Stems gray-green to gray, simple or with 2-5 branches, 40-120(-300) cm, distally 8-20 mm diam., at midlength ca. 10 mm diam., often narrowed toward base; wood hollow, solid-surfaced cylinders, 4-7 mm diam.; ribs 4-6, prominent; areoles (3.5-)12(-15) mm apart along ribs, circular to elliptic, 2-5 × 2 mm. Spines (9-)11-15(-17) per areole, usually in 3 vertical rows; abaxial 3-5 spines appressed, yellowish white throughout or only at tips, to 3 mm, puberulent when young; adaxial spines black, subulate, to 1 mm. Flowers: nocturnal (remaining open next day), 15-25 cm; scales of flower tubes green, tipped red or brown; outer tepals greenish white with brown to reddish midstripes; inner tepals white or lightly tinged cream or pink (or rarely all rose-pink), lanceolate-attenuate, apiculate, 4-7 cm, attenuate to mucronate; stamens 2.5 cm; anthers cream-yellow, 2 mm; style white, 10-14 cm; stigma lobes 9-11, white. Fruits bright red, darkening in age, ellipsoid, 60-90 × 40-50 mm. Seeds 3-4 × 2-2.5 mm. 2n = 22.
Plant: Shrubs erect to sprawling, sparingly branched, inconspicuous, 0.4-1.2(-3) m tall; root solitary, large, light-brown, napiform, usually 15-30 cm long, 5--12 cm wide, but much larger ones are known . STEM gray-green to gray to purple, the distal parts 8-25 mm in diameter, bearing 4-6 prominent, angular, papillose-canescent ribs, the basal parts usually narrowed, brown and cylindric. AREOLES white-woolly, aging gray to blackish, (3.5-)4.5-12(-15) mm apart on each rib Leaves: SPINES black to yellowish-white, (9-)11-15(-17) per areole, usually in 3 vertical rows; apical ones black, subulate to 1 mm long; basal 3-5 spines yellowish white throughout to only at tips, thinner, to 3 mm long, appressed, puberulent when young Flowers: 15-25 cm long, 5-12 cm wide; floral tube papillose-canescent, the scales green tipped red or brown; tepals 4-7 cm long, lanceolate, attenuate to mucronate, the outer ones greenish white with brown to reddish midstripes, the inner ones white or lightly tinged cream or pink or rarely all pale rose pink; stamen filaments white, the anthers very pale cream-yellow Fruit: FRUITS bright red darkening in age, spiny, ellipsoid, snouted, 3-10.5 cm long, 2-5 cm in diameter; pulp red, fleshy, edible. SEEDS black, tessellate, wrinkled at hilum region, ca. 3-4 mm long, 2-2.5 mm wide REFERENCES: Pinkava, Donald J. 1995. Cactaceae. J. Ariz. - Nev. Acad. Sci. 29(1): 2, 6