Astrophytum myriostigma, known as the bishop's cap, is a spineless Mexican cactus, famous for its star-shaped outline and its surface covered in fine white scales.
| Kingdom | Plantae |
| Division | Magnoliophyta |
| Class | Magnoliopsida |
| Order | Caryophyllales |
| Family | Cactaceae |
| Genus | Astrophytum |
| Species | Astrophytum myriostigma |
Astrophytum myriostigma, commonly known as the bishop's cap or bishop's hat, is a spineless cactus that usually grows singly. Its stem, which ranges from globular to cylindrical, can reach 60 to 100 cm in height.
It has 5 to 8 pronounced vertical ribs and is covered in tiny white scales (trichomes) that give it its characteristic chalky white or silvery grey appearance. When the stem is cut across, its cross-section shows an almost perfect star shape.
It is endemic to north-eastern Mexico, where it grows in desert biomes and dry scrub, between 750 and 1,500 m above sea level, on stony, limestone soils.
It can take up to six years to flower for the first time. When it does, it produces funnel-shaped yellow flowers of up to 7 cm, sweetly scented.
Its genus name, Astrophytum, comes from the Greek astro (star) and phyton (plant) — literally, “star-shaped plant” — in direct reference to its outline.
The common name “bishop's cap” comes from the resemblance of its star-shaped cross-section to the mitre worn by bishops at religious ceremonies.
