A caudex-forming Euphorbiaceae described by Hook. in 1848, native across Central America and the Caribbean. Its grey-green, bottle-shaped trunk — the classic "Buddha belly" — gives it both its English and Japanese vernacular names, and from its crown, large peltate, palmately-lobed leaves spread like umbrellas. Long flower stalks lift dense clusters of orange-red coral-like blooms that persist for months, making it one of the most ornamental caudex plants in cultivation. It grows fast — seedlings can flower within two to three years — and is widely treated as a beginner's gateway to caudex collecting. Be warned, though: every part of the plant is toxic (phorbol esters), and the seeds in particular have caused fatal poisonings.
Native climate
Rainfall is spread fairly evenly across the year. Overall a warm climate.
A broad-scale picture of the native range. Real growing spots — rock crevices, fog belts — can be milder.
Sources: climate & elevation WorldClim 2.1 (1970–2000) · occurrences GBIF · native range POWO
Care
Light & Placement
Native to the dry deciduous forests and rocky slopes of Central America under strong sun, it appreciates bright light. Give it full sun outdoors during the growing season for a tight, compact trunk and short petioles. In Japan's midsummer, leaves can scorch under the combination of intense sun and heat, so light shading at around 30% is helpful, with the pot raised on a bench for airflow. When leaves drop in autumn, move it to a bright indoor window kept above 10°C. The species is genuinely cold-sensitive and should never be left outdoors through Japanese winter.
Watering
In active growth, water thoroughly once the surface dries — this plumps the trunk. After leaf-drop, hold the plant essentially dry through dormancy with at most a monthly misting.
Substrate
Drainage first, inorganic-led. Akadama : Kanuma : pumice = 4:3:3. A taller pot helps keep wet–dry cycles clean and the trunk healthy.
Fertilizer & Supplements
A diluted liquid feed once or twice a month in active growth, or a pinch of slow-release at repotting. The species grows fast and responds well to modest feeding.
Temperature & Overwintering
Active growth runs 22–35°C; aim for a 10°C minimum. The plant is cold-sensitive — exposure below 5°C frequently damages or kills the trunk. Move it under cover early in autumn and overwinter dry on a bright indoor window.
Starting from Seed
Where to source seeds
Pre-sowing treatment
Soak seeds for about half a day (overnight) in a mix of a registered seed-treatment fungicide (Benlate or Daconil) and a plant tonic (Menedael; outside Japan, SUPERthrive or a chelated iron / seaweed extract works similarly), each diluted per label. Floaters are usually no longer viable. Seeds are large and easy to handle, but never crack them open with bare hands — they are highly toxic.
Substrate
A fine-grained, near-sterile seedling mix: fine Akadama, fine Kanuma, vermiculite in 1:1:1 parts. Sterilize with boiling water or a microwave pass for safety.
Sowing method
Seeds are large enough to press lightly into the surface and cover with about 5 mm of substrate. Space at least 2 cm apart.
Light & temperature
Bright shade at a steady 25–30°C. Expect germination in 7–21 days. Germination depends strongly on seed freshness, but fresh seed tends to come up well.
Watering
Bottom-water with the level 1–2 cm up the pot. For the first 2–3 weeks, don't let things dry out, then drop the level gradually as seedlings come up.
Fertilizer
No feeding right after germination. Once true leaves emerge, give a heavily diluted liquid fertilizer once or twice a month — growth is brisk without pushing the dose.
From Germination to Repotting
Germination through true leaves
Continue bottom watering, avoid strong light.
Weaning off bottom watering
Transition gradually over 1–2 months.
First repotting
In the first year, once the plant has become root-bound.
Common Pitfalls
Mold & damping-off
- Cause: excess moisture, contamination, poor air flow
- Prevention: sterilize substrate, change bottom water frequently
Etiolation
- Cause: insufficient light, heat-and-humidity stress
- Prevention: bring LEDs closer right after germination, or move to bright shade outdoors
Seeds fail to germinate
- Cause: stale seed, insufficient warmth
- Prevention: fresh seed and 25–30°C on a heat mat
Notes
The seeds are toxic; keep them out of reach of children and pets.
