Jellyfish Head - Euphorbia stellata

Flower: Greenish-yellow in cymes.

Growth rate: It is a slow growing species.

Soil and pots: It likes pots with generous drain holes, needs a very airy potting medium.

Exposure: This plant has an excellent heat tolerance and needs full sun to light shade exposures. It grows well even in full blasting sun but can tolerate moderate shade.

Watering: Water regularly during the active growing season. No water should ever be allowed to stand around the roots. Keep almost completely dry in winter.
Hardiness: Some cold tolerance. This spurge has tolerated temperatures down to -6ºC.

Some of the information in this description has been found at desert-tropicals.com, llifle.com and cactus-art.biz