Devil's Tongue
Sources last read 14 September 2026.
Not yet rated How forgiving it is has not been judged here yet.
Also called Elephant Yam, Konjac, konnyaku, Konnyaku Potato, snake palm, umbrella arum and Voodoo lily.
Devil's Tongue is toxic
- Not assessed for cats. This plant is not on the ASPCA list. That is not a finding of safety: none of the sources read for this site gives an answer either way. Treat it as unknown.
- Not assessed for dogs. This plant is not on the ASPCA list. That is not a finding of safety: none of the sources read for this site gives an answer either way. Treat it as unknown.
- Toxic to people. Harmful when eaten; irritates skin and eyes. Use gloves and protective gear when handling it. RHS
What the sources say about its care
- Light
- Partial shadeRHS · read 13 September 2026
- Water
- Moist but well-drainedRHS · read 13 September 2026
- Humidity
No source read publishes a humidity figure for any plant on this site. What follows is general guidance for foliage plants.
ASHRAE recommends indoor relative humidity between 30% and 60% 30–60%Penn State Extension · read 13 September 2026- Temperature
How cold this tolerates, not what it prefers. No source read for this site publishes a preferred range for a plant indoors.
H1B — 10–15°C 10–15 °CRHS · read 13 September 2026- Soil
- Loam; pH Acid or Alkaline or NeutralRHS · read 13 September 2026
- Toxic to cats
- Not on the ASPCA list. That is not a finding of safety.ASPCA · read 13 September 2026
- Toxic to dogs
- Not on the ASPCA list. That is not a finding of safety.ASPCA · read 13 September 2026
- Harmful to people
- Harmful when eaten; irritates skin and eyes. Use gloves and protective gear when handling it.RHS · read 13 September 2026
Routine care
- Watering
- Water less while the plant is dormant in winter.NC State Extension · read 13 September 2026Give filtered light; water and feed during active growth, and overwinter somewhere warm with the compost barely moist.RHS · read 13 September 2026
- Feeding
- Feed on a regular schedule.NC State Extension · read 13 September 2026Keep in filtered light; during active growth give water and feed, and overwinter somewhere warm with the compost barely moist.RHS · read 13 September 2026
- Propagation
- Use offsets (cormels) or seeds to propagate.NC State Extension · read 13 September 2026Detach offsets while dormant, or sow seed with heat during autumn or early spring.RHS · read 13 September 2026
- Pruning
- Pruning is not needed.RHS · read 13 September 2026
- Pests and diseases
- Diseases: damping-off in seedlings.NC State Extension · read 13 September 2026Usually free of pests and diseases.RHS · read 13 September 2026
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Photographs
About the plant
Amorphophallus konjac, commonly known as juruo, konnyaku or konjac, or moyu, is a species of flowering plant in the family Araceae. In English, it is also referred to as devil's tongue, voodoo lily, snake palm, or elephant yam.
From Wikipedia, CC BY-SA 4.0 · read 13 September 2026
- Native range
- China (Yunnan)World Checklist of Vascular Plants, June 2026 release, CC BY.Kew WCVP · read 13 September 2026East Asia and southwest ChinaNC State Extension · read 13 September 2026Indonesia to JapanRHS · read 13 September 2026
- Climate
- wet tropicalWorld Checklist of Vascular Plants, June 2026 release, CC BY.Kew WCVP · read 13 September 2026
- Growth form
- tuberous geophyteWorld Checklist of Vascular Plants, June 2026 release, CC BY.Kew WCVP · read 13 September 2026Bulb, Herbaceous Perennial; habit erectNC State Extension · read 13 September 2026Columnar upright (deciduous)RHS · read 13 September 2026
- Size
- Height up to 51 in; width up to 51 inNC State Extension · read 13 September 2026Height 1-1.5 metres; spread 1-1.5 metres after 5–10 yearsRHS · read 13 September 2026
- Flowering
- Flowers brown/copper, purple/lavender, red/burgundyNC State Extension · read 13 September 2026Flowers brown in summer; purple in summerRHS · read 13 September 2026
- Uses
What sources record people using this plant for. A traditional or medicinal use listed here is a record of use, not advice to eat it or treat anything with it.
In Asia it is eaten and used in traditional medicine. In Japan the corm is valued as a source of konnyaku, a flour used in many diet foods and in jelly. The starchy tubers can be eaten when cooked as potatoes are, and are often dried and milled into flour for noodles and tofu. They can be toxic raw.NC State Extension · read 13 September 2026
More of the Araceae family
Arrowhead plantEdges of the leaf blades brown while the middle stays sound
Calla lilyEdges of the leaves brown while the middle stays sound
Dumb caneLeaf tips go crisp and brown
Elephant earCrisp margins that appear in winter
Flamingo flowerBrown brittle margins with a green centre
Heartleaf philodendronA thin dry rim that crumbles between the fingers
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Sources
- ASPCA · read 13 September 2026
- Kew WCVP · read 13 September 2026
- NC State Extension · read 13 September 2026
- Penn State Extension · read 13 September 2026
- RHS · read 13 September 2026
- Wikipedia · read 13 September 2026
What this does not cover
The figures above are what published sources say, not measurements of the plant in your room. They say nothing about your pot size, your water, the season, or how far from the glass the plant stands, and those decide more than any figure here does.
Humidity has no species figure because no source read for this site publishes one, and the only temperature published for this plant is a cold floor. The simulator fills those gaps with general figures for its kind of plant, marked as general and listed on how we read sources. Where a toxicity row says the plant was not assessed, that is the absence of a finding and not a finding of safety.
If something is already wrong, the diagnosis tool asks about the soil, the window and the watering, which is where the answer usually is.