This species is named for its many-ribbed stems (15 – 26), compared with other species in the genus, and has golden spines that become long and flexible near the flowering apex. We offer rooted cuts of HBG 18990, grown from seed received in 1965, collected by Friedrich Ritter (FR 1346) at the type locality on quartz rocks at Itaobim, Minas Gerais, Brazil. $7.
Published in the Cactus and Succulent Journal, Vol. 89 (3), May-June, 2017