Pilosocereus leucocephalus, called old man cactus (along with a number of similar species), old man of Mexico, tuno, and woolly torch, is a species of cactus in the genus Pilosocereus, native to Mexico and Central America.

[2] It has gained the Royal Horticultural Society's Award of Garden Merit.

[3] Pilosocereus leucocephalus functions as a keystone species in dry landscapes found in Mesoamerica.

The fruit this cactus produces is relied upon as a source of hydration and sugar in arid areas by frugivores such as birds, bats, and even some reptiles.

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