A small Euphorbia from a tight range of sandy coastal forest around Tôlanaro in southeastern Madagascar. It carries a tuberous, caudex-like stem mostly below ground, while above the soil it spreads spoon- and paddle-shaped leaves low and wide. Leaf color varies a great deal from plant to plant — green, near-black, silver, some with red veining — and it has a following among collectors who enjoy that variation. POWO treats it as a synonym of Euphorbia decaryi var. decaryi, but the name Euphorbia francoisii is firmly established in horticulture, so this site follows that usage. With its habitat shrinking, it is listed as threatened on the IUCN Red List, and as one of a group of succulent Madagascan euphorbias it sits on CITES Appendix I.
Native climate
Rain concentrates in the warm season, with a distinct dry season. Overall a warm climate.
* Accurate distribution data is scarce for this species, so these values are taken from the climate near the approximate center of its native range instead.
Sources: climate & elevation WorldClim 2.1 (1970–2000) · occurrences GBIF · native range POWO · current weather Open-Meteo
Care
Light & Placement
Native to low-elevation, sandy coastal forest under bright sun and a clear wet–dry rhythm, it does best in bright airflow during the growing season. Outdoors, only Japan's peak summer needs a light 30–40% shade; otherwise about half a day of direct sun keeps the leaves compact and well-colored. Because it is low-growing and very much a leafy type, too much direct sun tends to mark the leaves, and it holds its form well in brighter half-shade. Keep the pot raised, sheltered from rain as a default. In winter, bring it to a bright indoor window, kept on the dry side, with an 8°C floor.
Watering
In active growth, water thoroughly once the substrate has fully dried, then let it dry again. Prolonged rain, or cold plus damp soil in winter, goes straight to rot in the underground stem, so keep it out of the rain. Once it drops its leaves in dormancy, taper to a light misting once or twice a month.
Substrate
Drainage above all, in an inorganic mix. Small-grain Akadama : Kanuma : pumice = 4:3:3 is a reliable baseline. A pinch of slow-release such as Magamp K helps early growth, and a taller pot improves the wet–dry cycle.
Fertilizer & Supplements
A small amount of slow-release in active growth, plus a monthly dilute liquid feed (around twice the label dilution). Overfeeding pushes leafy, stretched growth and slows the filling-out of the underground stem — aim to grow it on the lean side.
Temperature & Overwintering
Optimal 20–32°C, with an 8°C winter floor. As a low-elevation coastal plant it leans cold-sensitive; below 5°C the leaves and stem are prone to damage. From autumn, taper water in stages and overwinter fully dry on a bright indoor window, out of rain.
Starting from Seed
Where to source seeds
Pre-sowing treatment
Soak seeds for about half a day 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 empty. Seed of this species is scarce on the market, so sow as soon after arrival as you can.
Substrate
Use a separate seedling mix that's fine-grained and near-sterile: fine Akadama, fine Kanuma, and vermiculite in equal 1:1:1 parts. Sterilize the mix with boiling water or a quick microwave pass before sowing.
Sowing method
Sow with no covering, or only the thinnest dusting of substrate so the seeds remain partly visible. Space them at least 1 cm apart so they don't clump or overlap on the surface.
Light & temperature
Keep the tray in bright shade at a steady 25–30°C. Expect germination in 7–21 days. Germination depends on seed freshness, but with fresh seed it is reasonably steady.
Watering
Bottom-water with the level 1–2 cm up the pot. For the first 2–3 weeks, prioritize not letting things dry at all, then drop the level in steady stages once the seedlings have come up.
Fertilizer
No feeding right after germination. Once the true leaves emerge, give a heavily diluted liquid fertilizer once or twice a month — go lighter than the label suggests for safety.
From Germination to Repotting
Germination through true leaves
Continue bottom watering and avoid strong light.
Weaning off bottom watering
Wean off gradually over 1–2 months.
First repotting
In year 1 or 2, once the plant becomes root-bound.
Common Pitfalls
Mold & damping-off
- Cause: Excess moisture, contamination, poor airflow
- Prevention: Sterilize the substrate, change bottom-water often, run a fan for airflow
Etiolation
- Cause: Insufficient light
- Prevention: Move the LED closer right after germination, or move outdoors to bright shade
Seeds fail to germinate
- Cause: Stale seeds, insufficient temperature
- Prevention: Source from a trusted seller and use a heat mat to hold temperature
Notes
The latex can irritate skin and eyes — take care with hands and mucous membranes. Wild-collected plants fall under CITES Appendix I; seek seed-grown stock through proper channels.
