Trout lily (yellow adder’s tongue) Erythronium americanum
Trout lily (yellow adder’s tongue) (Erythronium americanum) is a deciduous perennial flowering plant in the Liliaceae family, native to Rich deciduous woods of eastern North America. It grows 10–20 cm (4–8 in) tall and 10–15 cm (4–6 in) wide, wants part sun to part shade and moderate water, and is hardy to about -35 °C (-31 °F). Space plants about 10 cm (4 in) apart.
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Trout lily (yellow adder’s tongue) at a glance
| Type | Perennial flowering plant, deciduous |
|---|---|
| Family | Liliaceae |
| Mature height | 10–20 cm (4–8 in) |
| Mature spread | 10–15 cm (4–6 in) |
| Spacing | 10 cm (4 in) centre to centre |
| Sun | Part sun to part shade, at least 3 h of direct sun a day |
| Water | Moderate; drought tolerance low, waterlogging tolerance low |
| Soil pH | 5.5–7 |
| Cold hardiness | About -35 °C (-31 °F) once established (roughly USDA zone 3) |
| Heat stress | Likely above about 30 °C (86 °F) |
| Flowering | from about April for 1–3 weeks (northern hemisphere; later in cold climates, earlier in warm ones) |
| Wind tolerance | Low |
| Pollinator value | Moderate |
| Edible | Not grown as food |
| Native to | Rich deciduous woods of eastern North America |
| Common in gardens of | 🇺🇸 United States, 🇨🇦 Canada, 🇬🇧 United Kingdom |
Is Trout lily (yellow adder’s tongue) toxic?
- People: mildly toxic
- Cats: not well documented
- Dogs: not well documented
- Parts: leaves, corms
Eaten raw in quantity it can cause vomiting; not a known danger to pets, though it is a close relative of lilies, so keep cats away.
If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.
Companion planting: what to grow with Trout lily (yellow adder’s tongue)
No well-documented helpful pairing. Group it with plants that like part sun to part shade and moderate water.
Questions about Trout lily (yellow adder’s tongue)
- How far apart should I plant Trout lily (yellow adder’s tongue)?
- About 10 cm (4 in) apart, centre to centre. A mature plant spreads 10–15 cm (4–6 in).
- Does Trout lily (yellow adder’s tongue) need full sun?
- Part sun to part shade: at least 3 hours of direct sun a day.
- How much water does Trout lily (yellow adder’s tongue) need?
- Moderate water. Drought tolerance is low and waterlogging tolerance low.
- How cold-hardy is Trout lily (yellow adder’s tongue)?
- It tolerates about -35 °C (-31 °F) once established, roughly USDA zone 3.
- When does Trout lily (yellow adder’s tongue) flower?
- From about April for 1–3 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
- Is Trout lily (yellow adder’s tongue) poisonous to cats and dogs?
- For cats it is not well documented; for dogs not well documented; for people mildly toxic. Eaten raw in quantity it can cause vomiting; not a known danger to pets, though it is a close relative of lilies, so keep cats away.
- What grows well with Trout lily (yellow adder’s tongue)?
- There is no well-documented companion pairing for Trout lily (yellow adder’s tongue). Group it with plants that like the same sun (part sun to part shade) and water (moderate).
Sources and evidence
Evidence grade A (A: strong evidence).
- Plants of the World Online (taxonomy, native range), Royal Botanic Gardens, Kew
- Missouri Botanical Garden Plant Finder, Missouri Botanical Garden
- Illinois Wildflowers (descriptions and insect-visitor records), John Hilty, illinoiswildflowers.info
Notes and assumptions
- A spring ephemeral of eastern woodlands: it flowers and leafs out before the trees close their canopy, then dies back by midsummer. Plant under deciduous trees in leafy, moist soil.
- Paired leaves mottled brown like a brook trout and nodding yellow lily flowers with swept-back petals in early spring. Colonies spread for centuries, but only plants with two leaves flower; a seedling takes several years to bloom.
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.
Related plants
- Lily Lilium
- Tulip Tulipa gesneriana
- Crown imperial Fritillaria imperialis
- Toad lily Tricyrtis hirta
- Snake’s head fritillary Fritillaria meleagris
- Madonna lily Lilium candidum
- Regal lily Lilium regale
- Easter lily Lilium longiflorum