[2] Echinocereus longisetus branches from the base, forming large clusters up to 1 meter in diameter.

The plant has four to nine central spines that are straight or curly, whitish to brownish, and 1 to 10 cm (0.39 to 3.94 in) long.

The funnel-shaped flowers are slightly pinkish-purple and appear near the base of the stems, not at the tips.

[3][4] There are two recognized subspecies:[2] Echinocereus longisetus is found in the Mexican states of Coahuila and Nuevo León.

Originally described as Cereus longisetus by George Engelmann in 1856, the specific epithet "longisetus" comes from the Latin words "longus" (long) and "-setus" (bristly), referring to its long, bristle-like spines.