Astrophytum

Astrophytum asterias

A low, flattened, spineless stem, usually eight ribs and large woolly areoles. Mexico and southern Texas.

Astrophytum capricorne

Long, flexible, twisted spines. Variable spination, flowers with coloured centres and seeds that float.

Astrophytum caput-medusae

A short stem axis, storage root and long, narrow tubercles. Separate spine-bearing and flower-bearing areoles.

Dense pale hairs, usually five ribs and fruits opening at the base. Similarity to myriostigma and species distinctiveness.

Bishop's cap. Variable rib number, hair cover and growth form. Two subspecies and numerous horticultural forms.

Astrophytum ornatum

Strong, rigid spines and banded hairs. A large, columnar body with age and distinct overwintering needs.