Astrophytum myriostigma Lem.
Bishop's Cap Cactus, Bishop's Cap, Bishop's-Cap, Bishop's Hat, Bishop's Miter Cactus, Bishop's-Hood
Astrophytum myriostigma is a spineless cactus with a usually solitary stem or with very few basal branches. The stem is globular to cylindrical, bright green, and covered with many tiny white hairy scales. It usually has five ribs and grows up to 3.3 feet (1 m) tall and 8 inches (20 cm) in diameter. The sweet-scented flowers are glossy yellow, funnel-shaped, up to 3 inches (7.5 cm) long, and appear from the areoles at the tip of the stem. Fruits are up to 1 inch (2.5 cm) in diameter, greenish to tannish-red, and covered with overlapping brown scales with long wool in their axil.
USDA hardiness zone 9a to 11b: from 20 °F (−6.7 °C) to 50 °F (+10 °C).
How to Grow and Care
Bishop's Cap is one of the easiest Astrophytums to grow. It is sometimes seen as a grafted plant but grows very well on its roots too. Like other star cacti, it does not ask for much water and thrives even with a very small root zone. However, they demand fast drainage overall and are downright hard to kill except with excessive moisture and rich soils. The very slow growth and small size make them ideal for bonsai pots and other creative containers on the porch, window sill, or balcony. This is ideal for beginners due to its lack of thorns, exceptional geometry, and ease of cultivation indoors.
Bishop's Cap is cold-hardy to about 20 °F (−6.7 °C). It should be given light shade for best results, although it will tolerate full sun. It should be given moderate water during the summer, but it should be kept dry as soon as the temperature starts dropping and keep it perfectly dry in winter at temperatures from 40 to 60 °F (5 to 15 °C). Bishop's Cap grows much faster with a low nitrogen content fertilizer in spring and summer.
Learn more at How to Grow and Care for Astrophytum.
This species is native to the highlands of northeastern and central Mexico.
Varieties and Cultivars
- Astrophytum myriostigma var. nudum
- Astrophytum myriostigma var. quadricostatum
- Astrophytum myriostigma 'Onzuka'
- Astrophytum myriostigma 'Onzuka Quadricostatum'
- Back to genus Astrophytum
- Succupedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus
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