old-man cactus

[ ohld-man ]
/ ˈoʊldˌmæn /

noun

a Mexican cactus, Cephalocereus senilis, having a columnar body from 30 to 40 feet (9 to 12 meters) high with thatchlike, long, white hairs on the top, and red flowers with white centers.

Origin of old-man cactus

An Americanism dating back to 1895–1900