Scientific Name
Astrophytum myriostigma var. quadricostatum Borg
Accepted Scientific Name
Astrophytum myriostigma Lem.
Common Name(s)
Bishop's Cap Cactus, Bishop's Cap, Bishop's Hat, Bishop's Miter Cactus, Bishop's Hood
Synonym(s)
Astrophytum myriostigma subsp. quadricostatum, Astrophytum myriostigma var. quadricostatum-pubesente, Astrophytum quadratum, Echinocactus myriostigma subsp. quadricostatus, Echinocactus myriostigma var. quadricostatus
Scientific Classification
Family: Cactaceae
Subfamily: Cactoideae
Tribe: Cacteae
Genus: Astrophytum
Origin
Astrophytum myriostigma var. quadricostatum is native to the highlands of northern and central Mexico. It grows in rocky, calcareous soils at elevations ranging from 2,240 to 4,920 feet (750 to 1,500 m). It is not accepted as a separate variety and is treated as a synonym of Astrophytum myriostigma.
Description
Astrophytum myriostigma var. quadricostatum is a spineless cactus with a usually solitary, quadrangular to almost spherical stem when young, becoming columnar with age. It has four ribs instead of five, as in Astrophytum myriostigma subsp. myriostigma. The stem can grow up to 3 feet (90 cm) tall and 4 inches (10 cm) in diameter.
The pale yellow flowers can reach up to 3 inches (7.5 cm) in length and 2 inches (5 cm) in diameter. They appear in succession from spring to fall and last about two days.
Hardiness
USDA hardiness zones 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. Like other star cacti, it does not require much water and thrives even with a very small Spartan root zone. However, they demand fast drainage overall and are downright hard to kill except with excessive moisture and fertile soils. 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. During the summer, it should be given moderate water, but it should be kept dry as soon as the temperature starts dropping. It should also be perfectly dry in winter at temperatures between 40 and 60 °F (5 and 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.
Links
- 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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