Astrophytum capricorne var. senile
| Light | Bright light; a little shade from the harshest afternoon sun |
|---|---|
| Water | Sparingly; let the mix dry out fully between waterings, keep dry and cool in winter |
| Soil | Fast-draining mineral mix (see Soil and potting mix) |
| Temperature | Keep above freezing; roughly USDA zones 9b–11 |
| Propagation | Seed; care as for the parent species |
| Toxicity | Non-toxic to cats and dogs |
Astrophytum capricorne var. senile is a spiny variety of the goat's-horn cactus, Astrophytum capricorne, distinguished by an especially dense mass of long, curling, dark spines that all but hide the green body beneath them. The varietal name senile ("aged") nods to the shaggy, grey-bearded look that a mature plant takes on as its spines accumulate.
Description
Like the typical form, the plant is globular to shortly columnar with pronounced ribs, a dark green epidermis, and the scattered white flecks (trichome tufts) that give the genus its characteristic marbled appearance. What sets senile apart is the spination: the papery, twisting spines are notably longer, more numerous, and darker — often nearly black in youth, fading toward grey with age — and they curl and interlace so thickly that they cloak the body almost completely. As with the species, mature plants produce large, funnel-shaped yellow flowers, frequently with a red throat, borne near the crown. The heavy spine cover is a cosmetic and horticultural distinction rather than a sharp botanical line; many growers treat it as a selected form within the natural variability of Astrophytum capricorne.
Cultivation
Grow it exactly as you would the parent species — see Astrophytum capricorne for the full routine. In short: give it plenty of bright light (a touch of shade only against scorching afternoon sun), plant in a lean, fast-draining mineral mix, and water sparingly, letting the medium dry completely between drinks. Keep it dry and cool through winter to encourage a proper dormancy and next season's flowers; see Watering and Soil and potting mix for details.
Two notes specific to this heavily spined variety are worth keeping in mind. First, strong light really does bring out the best spination — plants grown too dim tend to produce sparser, weaker spines and lose the dense "bearded" character that makes the variety worth having. Second, that thick tangle of spines can trap moisture and debris against the body, so favour good airflow and take extra care not to let water sit in the crown, which invites rot.
See also
- Astrophytum capricorne — the parent species
- Astrophytum — the genus overview
- Soil and potting mix · Watering · Propagation — seed