Pachypodium baronii
| Light | Bright light to full sun; some protection from the most intense afternoon glare |
|---|---|
| Water | Regularly through the growing season; keep dry once dormant and leafless |
| Soil | Fast-draining mineral mix (see Soil and potting mix) |
| Temperature | Keep warm; frost-sensitive, USDA zones 10–11 |
| Propagation | Seed (primary); cuttings root reluctantly |
| Toxicity | Sap may irritate; keep away from pets and children |
Pachypodium baronii is a caudiciform succulent shrub endemic to northern Madagascar, grown for its swollen, bottle-shaped base and — unusually for the genus — its brilliant red flowers. Where most Pachypodium bloom in shades of white or yellow, P. baronii carries showy scarlet blooms with a paler throat, making it one of the most sought-after species in the genus. It is sometimes known by the local name bontaka.
Description
Pachypodium baronii forms a stout, bulbous base — the caudex — from which one or more slender, spiny branches rise, giving established plants an almost bottle- or club-shaped silhouette. The swollen base stores water and is the plant's most prized feature among collectors. The stems are armed with paired spines and carry glossy, deep-green leaves clustered toward the branch tips during the growing season.
The flowers are the species' great distinction: rich red to crimson, often with a lighter or whitish centre, borne on long stalks that lift the blooms clear of the foliage. Flowering typically occurs in the warmer months, and a well-grown plant in full bloom is a striking sight. The variety windsorii is a compact, small-growing form with an especially rounded caudex and vivid red flowers, popular where space is limited.
Distribution and habitat
The species is endemic to northern Madagascar, where it grows on rocky slopes and outcrops in seasonally dry, warm conditions. Like many Madagascan pachypodiums, it endures a marked wet-and-dry cycle: active growth during the rains and a leafless dormancy through the dry season, when the caudex sustains the plant on stored water.
Wild populations are threatened by habitat loss — including logging and fire — and by over-collection, and the species is assessed as Endangered. Unusually for the genus, in which most species fall under CITES Appendix II, P. baronii is listed on CITES Appendix I, so commercial international trade in wild-collected plants is essentially prohibited. Nursery-raised, seed-grown plants are widely available and are the responsible way to add this species to a collection; wild-collected material should be avoided.
Cultivation
Pachypodium baronii rewards warmth and light. Grow it in a very free-draining, mostly mineral mix in a pot that suits the caudex, in bright light or gentle full sun. During the warm growing season, water generously once the mix has begun to dry, and feed lightly to build the caudex and encourage flowering. As temperatures fall and the plant drops its leaves, taper off and keep it dry and warm through dormancy — cold, wet roots are the quickest route to rot.
This is a frost-tender, tropical species that resents cold far more than many of its highland relatives, so err on the side of extra warmth in winter. See Watering and Repotting for general technique.
Propagation
Seed is the standard and most reliable method. Fresh seed sown onto a warm, mineral surface and kept humid germinates well, and seedlings develop the caudex naturally over time. Cuttings can be attempted but root reluctantly and rarely form as handsome a base as seed-grown plants. Grafting is occasionally used to establish difficult material or to grow on slow forms. See Propagation — seed and Propagation — cuttings for full walkthroughs.
Common problems
- Rot — the commonest cause of loss, almost always from watering a dormant plant or using a mix that holds too much moisture; the caudex or stem softens and discolours.
- Cold damage — this warmth-loving species blackens and collapses if kept too cold and wet in winter.
- Pests — mealybugs (white fluff in leaf axils and on the caudex) and spider mites (fine webbing, stippled leaves) are the usual offenders. See Pests and diseases.
See also
- Pachypodium — the genus overview
- Madagascar — habitat and other endemic succulents
- Grafting · Soil and potting mix · Watering · Propagation — seed · Propagation — cuttings