Xerophyte

Seeds

Differing from all other cactus seeds in being winged. Pterocacti are the only case of anemophilous dispersion in cacti.

Description

Pterocactus valentiniSN|19631]]SN|19631]]i is a geophyte cactus, little branched from the base and cespitose. It is very polymorphous. Some plants has flattened spines remembering those of the genus Toumeya.

Roots

Tuberous or subtuberous, but rather small, 2-4 cm long.

Stem Segments

Short, thick, cylindrical but usually slightly tapering at both ends, circular in cross section, obtuse, 4-8 cm long, 1-1,5 cm in breadth, green, glaucescent to brownish-purple that breaks off easily.

Flowers

Dark brownish-grey, coppery or yellow.

Spines

25-30(-35), not distinct as centrals and radials, 4-5 mm long, all hyaline, yellow to nearly black, radiating, slender, somewhat fattened and retroversely plicate.

Fruits

up to 2 cm in diameter.

Areoles

Without wool