About Pilosocereus polygonus (Lam.) Byles & G.D.Rowley
When Pilosocereus polygonus is defined with a narrow circumscription, it is a cactus species with green to gray-green stems that bear 8–13 ribs. Its branches grow in an ascending pattern, and are sometimes fully upright. The areoles of this cactus hold rigid spines that reach up to 3 cm (1.2 in) long, and these spines are dull yellowish when they are new. Flowering areoles have dense tufts of silky hairs that grow up to 3 cm (1.2 in) long, while non-flowering areoles have much fewer hairs. The flowers themselves measure 5–7 cm (2.0–2.8 in) long, with reddish green outer tepals and white inner tepals. The fruit produced by this cactus is red.
