Engelmann's Hedgehog Cactus

Engelmann's hedgehog cactus usually grows in clusters, sometimes up to 20 and more stems. The bright magenta flowers bloom in April in its southern extremes to late May at northern locations. Flowers are borne at the upper half to one third of the stem and are funnelform in shape, up to 3.5 in (8.9 cm) long with dark-green stigmas. The fruit is spiny. At first the fruit is green, becoming pink and drying when ripe. Ripe fruits have spines that are easily detached. Seeds are black and about a tenth of an inch in size. Stems are initially cylindrical and erect in young plants, but later with the stem base lying on the ground. The stems are usually 1.5 to 3.5 in (3.8 to 8.9 cm) in diameter and up to 25 in (64 cm) high, and obscured by heavy spines. The plants have around 10 ribs, which are somewhat flattened and tuberculate. Spines are variable in color and size. Radial spines are short and needlelike, up to 0.8 in (2.0 cm) long, white, and arranged in a neat rosette. Central spines number 2 to 7 and are stout, usually twisted and angular, up to 3 in (7.6 cm) long and variable in color: bright yellow, dark brown, grey, and white. Chromosome count is 2n=44.

Engelmann's hedgehog cactus is one of the most common species of cactus in the south-western US (southern California, Arizona, southern Nevada, Utah) and Mexico (Baja California down to northern Baja California Sur, Sonora) at elevations from sea level to 2400 meters. There are a number of varieties of Echinocereus engelmannii, and some are rare. It grows in different dry habitats normally in well drained deserts in the Sonoran and Mojave deserts, chaparral, pinyon-juniper woodlands, grass, and Great Basin shrub in flats with fine sand on the plain, washes and canyons in the desert, and also in gravelly, sandy, or rocky hillsides, and in mountain ranges. The rich flora and diverse vegetation of the area includes, among others, Ferocactus cylindraceus, Cochemiea grahamii, Cochemiea tetrancistra, Echinocereus scopulorum, Fouquieria sp., Larrea tridentata, Parkinsonia microphylla, Fouquieria columnaris, Cylindropuntia leptocaulis, Cylindropuntia ramosissima, and Opuntia engelmannii. Engelmann's hedgehog cactus is abundant throughout its range.

Echinocereus engelmannii is used as a landscape plant in its native areas. In pot culture, this species requires well aerated gritty substrate and a hot and sunny location in the summer. During winter, this species tolerates light frost and wet (if well-drained) soil. In cultivation, this species usually does not bloom until it develops 2–3 branches.