Echinocereus longisetus

Echinocereus longisetus is a succulent in the cactus family. It comes from northern Mexico, including Coahuila and Nuevo León. Kew places it in desert or dry shrubland. The name Cereus longisetus refers to the same species. Its white, bristle-like spines give the stems a pale coat. These spines form much of the plant's visible outline.

Plants may keep one stem or branch at the base. Branching plants form groups up to 3.3 feet [1 metre] across. The upright, cylindrical stems have fibrous roots below them. LLIFLE gives stem lengths of 0.5–1.6 feet [0.15–0.5 metres]. Its brief species summary gives a lower maximum of 1 foot [0.3 metres]. Stems measure about 0.16–0.26 feet [0.05–0.08 metres] across. Low ribs run along them, with small bumps along each rib. Most stems have 11–14 ribs, though counts reach 10–17.

Round, yellowish areoles carry two sets of spines. Each has five to nine long central spines. These can be straight or curved and tend to point down. Their colour ranges from white to brownish. Shorter white radial spines spread around them. Together, the spines almost hide the stem beneath. The flowers form funnels in shades of pink-purple or purple. They often open low on the stems, rather than near their tips. Flowers can reach 0.23 feet [0.07 metres] long and wide. Most measure less than 0.16 feet [0.05 metres] across.

Strong sun helps keep growth compact and builds dense spines. In summer, this cactus needs sun and good airflow. It also needs water during hot weather. Yet excess water can cause rot, so drainage must be excellent. Winter care differs: keep the plant cool, bright, and dry. LLIFLE reports brief cold tolerance to about 16°F [−9°C]. This does not establish a reliable hardiness zone for every garden.

LLIFLE describes the species as fairly easy to grow. Its dense spines and purple flowers provide its main garden interest. In mild climates, it can grow outdoors in freely draining ground. Growers can raise new plants from seeds or cuttings. Rot from excess water is the main problem named. The supplied species evidence gives no fruit or flowering-season details. It also gives no basis for claims about edibility or toxicity.