Astrophytum asterias 'Star Shape'
Astrophytum asterias 'Star Shape is a selected form of the sand dollar cactus, Astrophytum asterias, bred by growers for exceptionally clean, even rib grooves and crisp radial symmetry. The name gathers together a line of selections — widely traded as "Star Shape Kabuto" — chosen so that the deep, sharply cut grooves between the ribs accentuate the plant's familiar eight-pointed star outline when viewed from above.
Because it is a selection of the ordinary species rather than a stable botanical variety, "Star Shape" describes a look rather than a single fixed clone: the goal in every seed generation is a body that reads as a clean, geometric star with symmetrical, well-defined segments.
Description
Like the parent species, a 'Star Shape' plant is a low, spineless, disc-shaped cactus divided into ribs (characteristically eight) that radiate from the central growing point. What sets the selection apart is the quality of those divisions: the grooves between the ribs are deep and evenly spaced, and the ribs themselves are broad and regular, so the outline forms a tidy, well-balanced star rather than a lopsided or shallow-ribbed disc. The areoles sit in their characteristic neat row along each rib crest, carrying tufts of white wool. Fine flecking of white trichome scale over a green body, and the pale yellow flowers with a reddish-orange throat borne from the crown, are all as in ordinary Astrophytum asterias — it is the evenness of the ribbing and overall symmetry that is being selected for, not flower or flecking traits.
Cultivation
Care is exactly as for the parent species; see Astrophytum asterias for full detail. In short: give bright light with a little protection from the fiercest afternoon sun, grow in a very free-draining mineral mix (see Soil and potting mix), and water sparingly, letting the compost dry out completely between waterings and keeping the plant dry and cool through winter dormancy (see Watering). Consistent, even light from above helps a symmetrical selection grow true to form — a plant turned regularly, or lit evenly, is less likely to develop toward one side and spoil the clean star outline. Grow it slightly hard rather than pushing it with rich feeding, which tends to bloat the body and blur the crisp rib definition that is the whole point of the selection.
See also
- Astrophytum asterias — the parent species
- Astrophytum — the genus overview
- Soil and potting mix · Watering · Propagation — seed