Astrophytum myriostigma, the bishop's cap cactus, bishop's hat or bishop's miter cactus, is a species of cactus native to the highlands of northeastern and central Mexico.

Synonyms include Echinocactus myriostigma, Astrophytum prismaticum, A. columnare, A. tulense, and A. nuda.

Morphology

Astrophytum myriostigma is a spineless cactus defined by the presence of three to seven (usually five) pronounced vertical ribs which define the cactus' shape when young (the genus name "astrophytum", literally, "star plant", is derived from the resulting star-like shape). As the cactus ages, more ribs may be added and it becomes more cylindrical in shape, growing up to about tall and in diameter. In the wild, globose to cylindrical stem is covered with a whitish flocking of trichomes. Some horticultural varieties lack the flocking.

Life cycle

In the wild, the cacti flower in early spring, so that their seeds can grow with summer rains. In cultivation this differs, and the plants may flower in summer. Plants produce one or more flowers diameter near the apex; the numerous tepals are creamy yellow, sometimes with an orange or red base. Pollinated flowers develop into a hairy reddish fruit about in diameter. Plants may take up to six years to flower. A. myriostigma is commonly grown as an ornamental plant in cactus collections.

Trivia

This plant has gained the Royal Horticultural Society's Award of Garden Merit.

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File:Bishop's Cap.JPG

File:Astrophytum myriostigma.jpg

File:Astrophytum myriostigma flower.jpg

File:AstrophytumMyriostigma.jpg

File:Astrophytum myriostigma 11.JPG

File:Astriphytum myriostigma 2.JPG|Old plant

File:Astrophytum myriostigma quadricostatum.JPG|A. myriostigma var. quadricostatum

File:Astrophytum myriostigma nudum 5.JPG|A. myriostigma var. nudum

File:Astrophytum myriostigma v. tricostatum 1.JPG|A. myriostigma var. tricostatum

File:Ast.myrio nud.jpg|Astrophytum myriostigma nudum with 4,5,6,7,8 ribs

File:HugeAstrophytumMyriostigma.jpg|Huge plant

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References

  • "Bishop's cap cactus". Encyclopædia Britannica. 28/7/2005.
  • "Bishop's Miter, Bishop's Cap" . www.desert-tropicals.com. 28/7/2005.
  • photos on www.AIAPS.org
  • photos on www.cactiguide.com