Astrophytum myriostigma 

(ass-tro-fii' tum mir-ee-o-stig' mah)

Common name: Bishop's Cap/Mitre

Family: Cactaceae, Cactus

Height x width: 4-6" x 2-4"

Growth rate: slow

Shape: spherical, 4-8 ribs covered with minute white-wooly scales (modified spines); spineless (unarmed); areoles (often raised areas, or depressions, from which spines emerge) along ridges of ribs brown, spineless

Flowers: yellow, often red-centered

Light: full sun

Temperature: warm, cool when inactive

Watering: dry between waterings

Fertility: low

Humidity: low

Soil: cactus mix, slightly alkaline prefered

Pests and Problems: root rot, scab, mealybugs

Growth habit, uses: desert garden, full sun

Other interest: native to northern Mexico and Texas; from the Greek aster meaning star, and phyton meaning plant, refering to the star shape; a very distinct shape, attractive flowers and so popular

Other culture: hardy outdoors to zones 8-9

Propagation: seed

Related Species:

Species differ in density of scales, spines, and rib number. They hybridize easily, and so many variations and cultivars are found.

asterias (ass-ter' ee-as)--Sand Dollar/Sea Urchin Cactus, hemispherical, straight to slightly spiralling grooves between ribs, spineless white areoles, bright yellow flowers with red throats

capricorne (ca-pri-corn')--Goat's Horn Cactus, spherical, pale green ribs with deep grooves between, long twisted yellowish spines from areoles, yellow flowers with red centers; var. minor only 2-4" tall

ornatum (or-naa' tum)--spherical young to columnar when mature, straight or occasionally spiralling ribs with cross bands of wooly scales between, brown or yellow spines from closely spaced areoles, yellow flowers


©Authored by Dr. Leonard Perry, Professor, University of Vermont as part of PSS121, Indoor Plants.

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