Monadenium stapelioides
| Light | Bright light to light shade; the 'Rubrum' form colours up best in strong light |
|---|---|
| Water | Moderate in growth; keep dry when leafless and resting in winter |
| Soil | Fast-draining gritty mix (see Soil and potting mix) |
| Temperature | Keep above about 10 °C; frost-tender, roughly USDA zone 10+ |
| Propagation | Stem cuttings (primary); also seed |
| Toxicity | Caustic milky latex — irritant to skin, eyes and if ingested; keep away from pets and children |
Monadenium stapelioides is a slender-stemmed succulent spurge from East Africa, grown for its softly tessellated green stems and, above all, for the popular Rubrum form, whose stems and leaves are flushed and mottled in deep maroon. Like other members of Monadenium it belongs to the spurge family (Euphorbiaceae) and carries the family's caustic milky latex. The species name refers to a fancied resemblance of the stems to those of the unrelated stapeliads.
Description
Monadenium stapelioides makes clusters of upright to sprawling cylindrical stems that branch from the base and lengthen over time. The stems are patterned with low, spirally arranged tubercles, giving the surface a gently faceted, tessellated look. Small, thin leaves appear toward the growing tips during active growth and are shed as the stems mature or when the plant rests, so older growth is often bare.
As a Monadenium, its tiny flowers sit within a specialised cup-like structure (a cyathium) topped by a hood-like bract, rather than the open showy blooms of many other succulents — a subtle but characteristic feature of the genus. The much-grown Rubrum form differs only in colour: strong light develops rich reddish-maroon tones and darker mottling across the stems and leaves, while plants grown in shade revert to plainer green.
Distribution and habitat
The species is native to East Africa, where it grows in seasonally dry bush and rocky ground. In habitat it experiences a warm growing season with summer rains followed by a long dry rest, a rhythm worth keeping in mind in cultivation.
Cultivation
Monadenium stapelioides is an easygoing, undemanding succulent for a warm, bright spot. Grow it in a free-draining, gritty mix and water moderately while it is in leaf and growing, letting the mix dry out well between waterings. As the stems drop their leaves and growth slows, taper off water and keep the plant nearly dry through the cool months; wet, cold soil is the main cause of rot. See Watering and Repotting for general technique.
Give the Rubrum form as much light as it will take without scorching to bring out the best maroon colouration — in dim conditions it grows greener and more etiolated. All parts exude an irritant white latex when cut or broken, so handle with care, wash off any sap promptly, and keep it out of reach of pets and children.
Propagation
Stem cuttings are the easiest and most common method. Take a cutting in warm weather, rinse or blot the bleeding latex, and let the cut end callus and dry for several days before setting it in a dry, gritty mix to root. Seed is also possible where available. See Propagation — cuttings for a full walkthrough.
Common problems
- Rot — from overwatering or cold, wet soil during the rest period; stems soften and discolour, often from the base.
- Loss of colour / etiolation — too little light leaves the Rubrum form green and drawn, with weak, stretched stems.
- Pests — mealybugs (white fluff in the leaf axils and roots) and the occasional scale insect; see Pests and diseases.
See also
- Monadenium — the genus overview
- Euphorbia — the closely related genus into which Monadenium is now often placed
- Propagation — cuttings · Soil and potting mix · Watering · Repotting