Star Cactus
Astrophytum asterias
The Star Cactus (Astrophytum asterias) is a compact, spineless cactus native to Texas and northern Mexico. It's known for its symmetrical, flat-topped body, often segmented into 8 distinct ribs that create a star pattern when viewed from above. Covered in fine white dots (trichomes), it resembles a sea urchin or sand dollar — hence its other names.
This cactus is a favorite among collectors for its unusual form and stunning yellow flowers with orange centers that bloom from the crown in spring or summer. It’s extremely slow-growing and stays compact, making it ideal for small containers and sunny windowsills.
Quick Info
- Light: Bright
- Water: Low
- Size: 2–3 inches tall, 3–6 inches wide
- Humidity: Low
- Temp: 65–85°F (18–29°C)
- Flowering: Yes
- Type: Cactus
- Dog Safe: Yes
- Cat Safe: Yes
- Kid Safe: Yes
Toxicity Info
- Dog Safe: Yes
- Cat Safe: Yes
- Kid Safe: Yes
Care Instructions
- Place in a bright spot with several hours of direct sunlight
- Use a gritty cactus soil mix with fast drainage
- Water sparingly — typically once every 3–4 weeks
- Do not allow the cactus to sit in water; avoid misting
- Protect from cold drafts and overhandling
Common Problems
- Soft or shriveled body: Overwatering or underwatering
- No flowering: May need more light or maturity
- Discoloration: Stress from cold or intense direct sun without acclimation
FAQs
Not really — it’s essentially spineless, making it one of the safest cacti to handle.
In the wild, yes — it's endangered. But nursery-grown plants are widely available and legal to own.
Absolutely — just make sure it gets plenty of bright light and very little water.
Related Plants
Barrel Cactus
A round, spiny cactus with golden ribs and a striking sculptural look — the Barrel Cactus is a low-maintenance desert beauty perfect for sunny spots.
Fairy Castle Cactus
A charming, castle-like cactus with columnar stems that resemble towers — the Fairy Castle Cactus is a sculptural, slow-growing favorite for windowsills and small spaces.