Sunday, July 8, 2007

Astrophytum (2)


Let us continue with Astrophytum.

Astrophytum myriostigma, (common names: 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. coahuilense, A. tulense, and A. nuda.

A. 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 70-100 cm tall and 10-20 cm in diameter. The stem is often covered with whitish flecks.

The cactus flowers in the spring or summer with one or more waxy flowers 4-6 cm diameter near its apex; the numerous petals are yellow, sometimes with an orange or red base. Pollinated flowers develop into a hairy reddish fruit about 2-2.5 cm in diameter. Plants may take up to six years to flower. A. myriostigma is commonly grown as an ornamental plant in cactus collections.


Astrophytum ornatum needs moderate water in summer. Allow the soil to dry before watering again. Do not water in winter. The Astrophytum ornatum is the largest and one of the easiest to grow of the Astrophytums. It has 5 to 8 ribs (generally 8) and areoles have 5 to 11 brownish yellow spines, over 1 inch long (2.5 cm)

This Astrophytum is the easiest to grow and also the fastest. It responds well to half strength fertilizer in summer. To make sure that the fertilizer doesn't encourage growth instead of blossom, it might be better to wait until the flower buds start forming before using fertilizer.


The Astrophytum ornatum blooms in summer. The 2.5 inch wide flowers (6 cm) are pale yellow and scented. It needs to be 6 inches tall to bloom (15 cm). This might take six years or more depending on the length of its growing period in your local conditions.

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