Echinocereus rigidissimus subsp. rubispinus
Echinocereus rigidissimus subsp. rubispinus, often sold simply as the pink rainbow cactus, is a strikingly coloured form of the rainbow cactus whose comb-like spines glow in vivid shades of magenta, pink and wine-red. It is a naturally occurring, geographically restricted variant of Echinocereus rigidissimus, and where the typical rainbow cactus bands its columns in white, pink and rust, subsp. rubispinus concentrates that colouring into an almost uniform blaze of red-pink — the trait that makes it one of the most coveted rainbow cacti among collectors.
Its care follows the parent species, Echinocereus rigidissimus — see that page for the full account, with the notes below covering what is particular to this form.
Description
Like the type, subsp. rubispinus forms a solitary (occasionally clustering) short cylinder, densely clothed in fine, pectinate (comb-like) spines that press flat against the body and completely hide the green skin beneath. The distinguishing feature is colour: the spines run in bands of intense magenta to red, giving the whole plant a saturated pink-red cast rather than the softer, multi-hued banding of the ordinary rainbow cactus. Fresh growth at the crown is typically the brightest, with older growth fading and greying with age, so the plant carries a gradient from vivid tip to muted base.
Mature plants produce large, funnel-shaped flowers in shades of magenta-pink with a paler throat, borne near the top of the stem in late spring and summer — a spectacular contrast against the coloured spines.
Cultivation
Grow subsp. rubispinus exactly as you would the parent species: a gritty, fast-draining, mostly mineral mix, careful watering with a completely dry winter rest, and protection from freezing wet. As with all rainbow cacti it dislikes staying damp and rots easily if overwatered or left in heavy soil.
The one point worth stressing is light. The intense red-pink spine colour is strongest in very bright conditions; grown too dim, new growth comes through paler, greener and more sparsely spined, and the plant loses the very quality it is prized for. Give it the brightest spot you can, easing it into strong sun gradually to avoid scorching soft new growth. See Repotting for general handling of these tightly-spined, awkward-to-grip plants.
See also
- Echinocereus rigidissimus — the parent species
- Echinocereus — the genus overview
- Soil and potting mix · Watering · Repotting · Pests and diseases