Astrophytum ornatum "nudum"
Ribs are smooth and bright green.

Desription: The stem is solitary, globose when young , cylindric with age, up to 1,2m or more high, 15-30 cm across, dark green without (or with very few)  wooly flakes . It has 5 to 8 (generally 8)  straight or frequently spiraling, strongly compressed, more or less sinuate, crenate ribs.  Areoles at first yellowish-white felted, later grabrescent, with 5-10 stout, 2-4 cm long straight radial spines laterally compressed, amber yellow, later brown and finally grey, and usually 1 rather larger central spine.

Cultivation: This cactus is pretty cold hardy and can survive to -10° C (if kept dry)

Photo of conspecific taxa, varieties, forms and cultivars of Astrophytum asterias.

• Astrophytum ornatum
• Astrophytum ornatum var mirbelii
• Astrophytum ornatum var. virens
• Astrophytum ornatum forma cristata

Origin: Astrophytum ornatum is the southern genus of Astrophytum. The habitats are at Hidalgo, Queretaro and Guanajuato in Mexico.

Conservation status: Listed in CITES appendix 2.

Habitat:  grows in wild canyons and limestone cliffs.

Synonyms:  

• Astrophytum ornatum v. glabrescens
• Astrophytum ornatum v. glabrescens f. nudum
• Astrophytum ornatum v. virens
• Astrophytum ornatum f. nudum

The Astrophytum ornatum blooms in summer. The flowers (6-8 cm wide) are pale yellow with bright silken sheen and scented.

It needs to be at least 15 cm tall to bloom . This might take no less than seven years or more depending on the length of the growing period in the local climatic conditions.