Echinocereus rigidissimus

Echinocereus rigidissimus is a species of Echinocereus. It's type locality is Sonora.

Background
Plants simple, erect, rigid, short-cylindric, 1 to 2 dm. high, 4 to 10 cm. in diameter, usually hidden by the closely set interlocking spines; ribs numerous, 18 to 22, low; areoles approximate, elliptic, 5 to 6mm. long; radial spines about 16, gray to reddish brown, arranged in horizontal bands, pectinate, rigid, 15 mm. long or less, often recurved; central spines none; flowers purple, 6 to 7 cm. long, fully as broad when expanded; perianth-segments oblong, 3 to 4 cm. long, acute; stamens numerous, shorter than the style; areoles on ovary somewhat floccose, very spiny; fruit globular, 3 cm. in diameter, very spiny; seeds black, tuberculate, 1.5 mm. in diameter. Distributed in Southeastern Arizona and northern Sonora.