Astrophytum genus

The Astrophytum genus is comprised of 4 species of globose to short cylindrical cacti and one sprawling, octopus-like member. The first four were discovered between the years 1828 and 1845. Two of these are spineless and two have prominent spines. While each species is quite distinct, one from another these four feature a star-shaped appearance when viewed from above. Hence the name Astrophytum, which means start plant. Astrophytum species have been frequently compared to marine life, in particular A. asterias for its striking similarity to sea urchins.

The fifth member of this group was newly discovered in 2001. A. caput-madusae is quite distinct from the other members of the genus and actually very distinct from all other cacti genera as well. Hence, many enthusiasts feel it should be part of its own genus and cosider it to be the sole species in the genus Digitostigma. The name Digitostigma describes the long digit-like tubercles that grow something like an octopus.