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Bishop's Cap Cactus

Astrophytum myriostigma

succulent

verifiedReviewed by the GreenScout Team

A distinctive spineless or nearly spineless cactus with a geometric star-shaped body and white spots (scutellae) that give it a striking appearance. Produces pale yellow flowers with red centers in summer. A slow-growing Mexican native that makes an excellent focal specimen for collectors.

Common Problems

Select the problem your Bishop's Cap Cactus is experiencing to get a treatment guide.

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Root Rotchevron_right

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Overwateringchevron_right

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Mushy Stemschevron_right

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Pale Leaveschevron_right

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Slow Growthchevron_right

Care Guide

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Light

Bright light; prefers partial shade in very hot climates; requires at least 3–4 hours of direct sun

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Water

Water sparingly during growing season; minimize water in winter; allow soil to dry completely between waterings

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Soil

Extremely well-draining cactus mix with added coarse sand, perlite, or gravel; prioritize drainage

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Fertiliser

Minimal fertilizer needed; apply diluted cactus formula once or twice in spring only

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Temperature

Prefers 60–75°F (15–24°C); tolerates down to 35°F (2°C); benefits from cool winter rest

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Humidity

Very low; maintain dry, arid conditions; high humidity promotes rot and fungal issues

Toxicity

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Non-toxic; minimal hazard due to lack of significant spines

Common Diseases

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Common Pests

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Seasonal Care

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Resume regular watering and feeding as growth picks up.

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Peak growing season. Water and feed regularly.

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Reduce watering as growth slows. Stop heavy feeding.

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Minimal watering and feeding. Protect from frost if needed.

Frequently Asked Questions

Why does my Bishop's Cap Cactus have white speckles all over it?

Those white spots, called scutellae, are a natural feature of this species and give the star-shaped body its distinctive speckled appearance — they're not a sign of pest damage or disease.

Why does my Bishop's Cap Cactus grow so slowly?

Slow growth is simply typical of this Mexican native — it's prized as a focal specimen for collectors precisely because of its deliberate, unhurried growth habit, not because of a care problem.