Say it: air-ee-oh-CAR-pus fiss-yoo-RAY-tus. Common names: living rock, star rock, chautle.
Where it grows
The Big Bend region of west Texas and adjacent northern Mexico, on limestone flats and ridges in the Chihuahuan Desert. It sits almost flush with the ground and is nearly invisible when not in flower.
Size and growth
A flat rosette of triangular, deeply fissured grey-green tubercles over a huge taproot, usually 4–6 inches across. One of the slowest cacti: plants may take 8–12 years to flower from seed on their own roots. Mature plants are decades old.
Flowers
Bright magenta-pink flowers up to 2 inches across emerge from the woolly center in fall, often several at once — a shock of color on a plant that looks like a rock.
Care
- Light: full sun to bright light.
- Water: sparingly in summer, only when fully dry; completely dry in winter. Rot is the main risk.
- Soil: very mineral — pumice, grit and a little loam — in a deep pot for the taproot.
- Cold: surprisingly hardy when dry, to around 10–15°F.
From seed
Moderate. Germination in 10–30 days; seedlings are tiny and need months of humid tray life before hardening off. Ariocarpus is CITES Appendix I, so our seed ships within the US only.