Astrophytum asterias - Sand Dollar Cactus/Star Cactus

Morphological Characteristics

Astrophytum asterias is a spineless, disc-shaped cactus known for its distinct star-like form. It has 8 symmetrical ribs with small, woolly white areoles and is usually 5–15 cm (2–6 inches) in diameter. Its green epidermis is speckled with tiny white trichomes, giving it a dotted or “sand dollar” appearance. Unlike typical cacti, it has no spines, which enhances its clean, minimalistic shape. In bloom, it produces daisy-like yellow flowers with bright orange centers from the crown area.

Growth Habits

This is a slow-growing, solitary cactus with a non-clustering growth habit. It thrives best in stable, warm environments with low humidity. Due to its size and symmetrical aesthetics, it is a favorite among collectors and is best grown in shallow containers or decorative displays. Astrophytum asterias prefers to stay in the same pot for years and is particularly suited for indoor cultivation near sunny windows or in greenhouses with excellent ventilation.

Maintenance Points

Lighting: Needs bright light with partial sun. Morning sun is ideal; avoid harsh midday rays.

Watering: Infrequent but deep watering. Always allow soil to dry completely. Overwatering is fatal.

Soil: Use a gritty, fast-draining cactus mix with added pumice or perlite.

Temperature: Best between 70–85°F (21–29°C); must be protected from cold below 41°F (5°C).

Fertilizer: Feed with diluted cactus fertilizer monthly during spring and summer.

Handling: Handle gently to avoid bruising the soft epidermis.

Pests: Watch for mealybugs or root rot if overwatered or grown in poor airflow.