Astrophytum ornatum
Conservation status
Vulnerable  (IUCN 3.1)[1]
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Order:	Caryophyllales
Family:	Cactaceae
Subfamily:	Cactoideae
Genus:	Astrophytum
Species:	A. ornatum
Binomial name
Astrophytum ornatum (DC.) Britton & Rose

Astrophytum ornatum, the bishop's cap or monk's hood cactus, is a flowering plant of the family Cactaceae, endemic to the Central Plateau of Mexico. It is the largest and tallest species of Astrophytum.

Solitary and cylindrical in form, it may grow up to 2 metres (6.6 ft) in height and 30 centimetres (12 in) in width on the Central Plateau. It develops numerous white woolly flakes for protection from the sun. It flowers throughout the summer, the flowers being 7 to 8 centimeters long in canary yellow.

It is a rugged plant resistant to root rot, and easy to grow in a well-drained soil. It is dark green when grown in filtered light or shade. An established plant is cold tolerant to 25 °F (−4 °C).

Astrophytum ornatum has gained the Royal Horticultural Society's Award of Garden Merit.^[2]

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  It usually has 8 ribs, often in spiral
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  Flowers
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  Seeds
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  A one month old seedling
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  Astrophytum one year after sowing

• Media related to Astrophytum ornatum at Wikimedia Commons
• Astrophytum ornatum on Astroweb (in French)
• Astrophytum ornatum on Astrobase (in German)
• Simon & Schuster's Guide to Cacti and Succulents, Pizzetti, ISBN 0-671-60231-4
• photos on www.AIAPS.org (in French)
• "Star Cactus (Astrophytum ornatum)". (in English)
• photos on www.cactiguide.com (in English)