A rare Uncarina restricted to the limestone tsingy of the Ankarana region in northern Madagascar. Authority is Ihlenfeldt, 1967, with the specific epithet from the Ankarana area where it was first described. Mature plants reach 1–2 m, with deeply palmate leaves carrying more pronounced lobes than other Uncarina, and large yellow 5-petalled summer flowers. It is the only northern species in the genus — the other Uncarina are confined to southern and southwestern Madagascar on sandy substrates — and it roots in the cracks and bases of Ankarana's sharp limestone karst pillars. The hooked seed pods are the genus's shared feature. The thinnest-circulated species in the trade, picked up from seed by collectors drawn to its odd northern range and limestone affinity.
Native climate
Rain concentrates in the one season, with a distinct dry season. Overall a hot 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 · current weather Open-Meteo
Care
Light & Placement
A summer-grower from the limestone tsingy of Ankarana National Park, used to strong sun and a marked dry season. Full direct sun outdoors during the growing season keeps the deeply lobed leaves tight and supports flower production. A 20–30% shade cloth helps through Japan's worst midsummer; raise pots off the ground for airflow. Overwinter on a bright sunny window kept above 8°C and dry, sheltered from rain.
Watering
In active growth, water deeply once the substrate has dried, then dry it out fully again. The species comes from a limestone substrate so it tolerates a slightly alkaline mix, but as with the rest of the genus it is overwatering-sensitive. Taper as autumn cools, then go nearly dry through winter, with at most a single light misting per month.
Substrate
Drainage first, inorganic-led. Akadama : Kanuma : pumice = 4:3:3 is reliable. As a limestone-substrate species, a small pinch of dolomite lime nudges pH closer to its native conditions. A deeper pot suits the downward-running root.
Fertilizer & Supplements
A diluted liquid fertilizer monthly through active growth, or a small pinch of slow-release at repotting. The species is slow-growing, so pushing the dose mainly elongates branches without producing real thickening — keep doses modest.
Temperature & Overwintering
Optimal 22–35°C with an 8°C minimum. From the warmer climate of northern Madagascar, the species is cold-sensitive — branch tips suffer below 5°C. As autumn cools and leaves drop, taper water early and overwinter on a bright indoor window, holding the dry-warm rhythm until spring.
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. Seeds that don't sink are typically past their prime. The seed coat is hard, typical of Pedaliaceae — light scarification (gentle abrasion with sandpaper) improves water uptake.
Substrate
Use a separate seedling mix that's fine-grained and near-sterile: fine Akadama, fine Kanuma, and vermiculite in 1:1:1 parts. Sterilizing beforehand reduces damping-off.
Sowing method
Sow with no covering, or only the thinnest dusting so the seeds remain partly visible. Space at least 1 cm apart.
Light & temperature
Bright shade, 25–30°C steady. Germination spreads over 10–30 days; the species' very limited circulation means stale seed is more likely than for common Uncarina, so stay patient.
Watering
Bottom-water with the level 1–2 cm up the pot. For the first 2–3 weeks, prioritize not letting things dry out, then drop the water level gradually.
Fertilizer
No feeding right after germination. Once true leaves emerge, give diluted liquid fertilizer at double dilution, once or twice a month.
From Germination to Repotting
Germination through true leaves
Continue bottom watering, keep strong light off them.
Weaning off bottom watering
Phase out gradually over 1–2 months.
First repotting
In year one or two, once roots have filled the pot.
Common Pitfalls
Mold & damping-off
- Cause: excess moisture, contamination, poor air flow
- Prevention: sterilize the substrate, refresh the bottom-water, and use a circulation fan
Etiolation
- Cause: insufficient light
- Prevention: move LEDs closer right after germination, or shift the tray to bright shade outdoors
Seeds fail to germinate
- Cause: stale seed, insufficient warmth, hard seed coat blocking water uptake
- Prevention: source fresh seed from reputable sellers given the species' very thin trade circulation, lightly scarify before soaking, hold 25–30°C steady on a heat mat
Notes
Mature fruits carry sharp hooks that grip clothing and fingers tenaciously. Use leather gloves when pruning or harvesting seed.
