Gearstem Cactus

Shrubs, suberect to sprawling, very inconspicuous. Roots 12 or more, ending in sweet potato-like swellings, 10-15 × 4-7 cm. Stems greenish brown to brown, branched, 25-75(-100) cm, distally 6 mm diam., at midlength ca. 6 mm diam.; wood hollow, solid-surfaced cylinders, proximally 3-7 mm diam.; ribs 6-9, flat-topped to 2 mm broad, narrowing toward sinus, 0.5 mm deep, separated by narrow grooves; areoles 5-20 mm apart along ribs, circular, 1 mm diam. Spines 5-12 per areole, yellowish white, some with black tips, nearly acicular, weak and easily broken off, 1.5-4 mm; radial spines encircling central spines, abaxial 3 longest, appressed, scurfy when young; central spines 2-3 porrect. Flowers: nocturnal, 7-10 cm; scales of flower tubes green-purple to reddish; outer tepals reddish to green-purple; inner tepals white to lightly tinted rose, lanceolate to oblanceolate, 2 cm, attenuate to apiculate; stamens 1 cm; anthers pale lemon yellow, 1.5-2 mm; style yellow-white, 6 cm; stigma lobes 9, yellowish white. Fruits scarlet, pyriform, 40-50 × 25 mm, with bristlelike spines. Seeds 1 × 0.8 mm; testa pitted near hilum.

Ariz.; Mexico (Baja California Sur, Sinaloa, Sonora).

Flowering summer; fruiting summer-early fall.

Sonoran Desert, flats, small hills; 0-500m.

Cereus striatus Brandegee, Zoë 2: 19. 1891; C. diguetii F. A. C. Weber; Neoevansia diguetii (F. A. C. Weber) W. T. Marshall; N. striata (Brandegee) Sánchez-Mejorada; Peniocereus diguetii (F. A. C. Weber) Backeberg; Wilcoxia diguetii (F.A.C. Weber) Diguet & Guillaumin; W. striata (Brandegee) Britton & Rose