Stems solitary or few in a cluster, more or less conical, 10-15 cm tall, 7-10 cm wide; ribs 7-12, tubercled; spines usually 3-7 per areole, thick, to over 1 mm near swollen base, often angular in cross section, usually white to pale gray, sometimes brownish, often with a brown to purplish or black longitudinal line, one spine occasionally central and porrect to 2.5 or exceptionally 5 cm long, others spreading radially and usually not over 2.5 cm long; flowers 6-12 cm in diameter; tepals magenta, usually with bands of green and darker color near center, usually pointed; ovary spiny, spines deciduous with ripening of fruit, perianth persistent; mature fruit 3-5 cm long, broadly spindle-shaped, red with white somewhat juicy pulp, usually dehiscing by one to three longitudinal slits; seeds about 1.5 mm long, black, tubercled, hilum basal. Flowers in May to early June.
Echinocereus fendleri var. fendleri has a greater number of longer and more slender spines, typically less tubercled stems, and narrower fruits. Echinocereus triglochidiatus is usually clustering and larger, no dark line on spines, fewer ribs (5-7), and red flowers. Echinocererus coccineus var. gurneyi also has red flowers. Its stems are densely clustered; spines mostly terete. Juvenile plants of var. fendleri and var. rectispinus often look much like var. kuenzleri, but become typical of their respective varieties as they mature.
New Mexico, Chaves, Eddy, Lincoln, and Otero counties; southern side of the Capitan Mountains, eastern and northwestern lower sides of the Sacramento Mountains, and northern end of the Guadalupe Mountains.
Primarily on gentle, gravelly to rocky slopes and benches on limestone or limy sandstone, in Great Plains grassland, oak woodland, or piñon-juniper woodland. Elevation 1,600-2,000 m (5,200-6,600 ft).
This plant had been collected commercially in the past. Plants can be trampled where livestock congregate. In the short term fire diminishes populations of this species; the long-term population dynamics of this taxon in a fire-adapted ecosystem need to be studied.
*New Mexico Native Plants Protection Advisory Committee. 1984. A handbook of rare and endemic plants of New Mexico. University of New Mexico Press, Albuquerque.
Benson, L. 1982. The cacti of the United States and Canada. Stanford University Press, Stanford, California.
*Castetter, E.F., P. Pierce and K.H. Schwerin. 1976. A new cactus species and two new varieties from New Mexico. Cactus and Succulent Journal (U.S.) 48(2):77-78.
U.S. Fish and Wildlfie Service. 1979. Determination that Echinocereus kuenzleri is an endangered species. Federal Register 44(209):61924-61927.
U.S. Fish and Wildlife Service. 1985. Kuenzler hedgehog cactus (Echinocereus fendleri var. kuenzleri) recovery plan. U.S. Fish and Wildlife Service, Southwestern Region, Albuquerque, New Mexico. 44 pp.
*Weniger, D. 1991. Cacti of Texas and neighboring states. University of Texas Press, Austin, Texas.
Flora of North America Editorial Committee. 2003. Flora of North America, volume 4. Oxford University Press, New York.