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Erythronium americanum; photograph (c) Loïc Mathieu, some rights reserved (CC BY) CC BY(c) Loïc Mathieu, some rights reserved (CC BY) · observed growing wild · 2026-05-25

Erythronium americanum Ker Gawl.

Yellow adder's-tongue; Yellow trout lily; Amberbell; American trout lily

Liliaceae · Labrador, New Brunswick +32 · listed by its family as a bulb, tuber or caudex

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Erythronium americanum, photograph (c) Patrick Jackson, some rights reserved (CC BY)Erythronium americanum, photograph (c) Alex Novarro, some rights reserved (CC BY)Erythronium americanum, photograph (c) Jensyn Scott, some rights reserved (CC BY)Erythronium americanum, photograph author not stated, no rights reservedErythronium americanum, photograph (c) Cy Stavros, some rights reserved (CC BY)Erythronium americanum, photograph (c) Loïc Mathieu, some rights reserved (CC BY) 62 photographs ›
Habitat figures
Cold floor (1 night in 100)
-17.8°C
Record low -27.9 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
26°C
Jul at the habitat CHELSA
Rain a year (median across the range)
1,118mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
9–39DLI
Lowest to highest month (DLI) CHELSA
The year in your months, northern hemisphere
  1. Jan
  2. Feb
  3. Mar
  4. Apr
  5. May
  6. Jun
  7. Jul
  8. Aug
  9. Sep
  10. Oct
  11. Nov
  12. Dec
Rain spread: 70% of the median year's rain takes 8 months, so no short rainy season. rain rule, CHELSA
Northern hemisphere unless you set your site. The chart is in the habitat's months.

Summary

Erythronium americanum, the trout lily, yellow trout lily, fawn lily, yellow adder's-tongue, or yellow dogtooth violet, is a species of perennial, colony forming, spring ephemeral flower native to North America and dwelling in woodland habitats. Within its range it is a very common and widespread species, especially in eastern North America. The common name "trout lily" refers to the appearance of its gray-green leaves mottled with brown or gray, which allegedly resemble the coloring of brook trout.

Quoted from Wikipedia, "Erythronium americanum", CC BY-SA 4.0.

About the genus · Erythronium

Erythronium, the fawn lily, trout lily, dog's-tooth-violet or adder's tongue, is a genus of Eurasian and North American plants in the lily family, most closely related to tulips. The name Erythronium derives from Ancient Greek ἐρυθρός (eruthrós) "red" in Greek, referring to the red flowers of E. dens-canis. Of all the established species, most live in North America; only seven species are found in Europe and Asia.

Quoted from Wikipedia, "Erythronium", CC BY-SA 4.0.

Cultivation

Grouped as a bulb, tuber or caudex, listed under the family Liliaceae in the archetype table, and Kew describes it as “bulbous geophyte”.

Seasons

The rain rule reads no short rainy season: 70% of the median year's rain (795 mm of 1,116 mm) takes 8 months, April to November. Mean temperature moves 25.9 °C between the warmest and coldest month. Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: October to May.

Rain

1,116 mm in the median year at the habitat, 795 mm of it April to November. Wettest month July at 108 mm, driest month February at 71 mm. Across the grid cells of the range the year's total runs 906 mm to 1,359 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,118 mm, is the year's rain at the top of the page; the 1,116 mm here is the median year's, the twelve monthly medians added, which the rain rule reads. Habitat calendar, northern hemisphere; median year across the grid cells of the range, CHELSA.

Light

Open sky over the habitat: 9 to 39 mol/m²/day across the year (daily light integral, median year across the grid cells of the range, CHELSA; the lowest 10th-percentile month across the cells is 8, the highest 90th-percentile month 41).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is -17.8 °C, the absolute minimum -27.9 °C, 6,261 frost nights in 44 years, 142.3 a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 32.5 °C. Monthly means: the coldest month's mean nightly low -8.1 °C in January (across the grid cells of the range -14.3 °C to -3.0 °C), the warmest month's mean daily high 26.2 °C in July (median year across the grid cells of the range, CHELSA). Cold floor: -17.8 °C, which is the 1st-percentile night over 44 years at a typical spot in the range (NASA POWER).

Humidity

Relative humidity at the habitat: 56 to 61% across the year (monthly means, median year across the grid cells of the range, CHELSA). A figure about the air, saying nothing about how the plant takes water.

How this section is made

Each card states this species' habitat figures with their sources, and what two fixed rules read from them; nothing here says what the plant does, wants or tolerates. The rules · the terms.

Seasons. Read from the median year of CHELSA monthly rainfall and mean temperature across the grid cells of the range: the rain rule takes the smallest set of months carrying 70% of the rain and calls it winter when its mean is more than half a degree below the year's, summer when more than that above, and neither in between; the temperature rule, used only under 120 mm, names the cooler six months when they are at least a degree cooler than the other six. Months are shifted for the other hemisphere only where the temperature curve moves 4 °C or more and the habitat lies 10° or more from the equator. A reading of the curves, not an observation of the plant.

Rain. CHELSA monthly precipitation, median year across the grid cells of the range. The rain that falls where the species is recorded; nothing about how the plant takes water.

Light. CHELSA shortwave radiation at each envelope cell, a daily-mean flux taken to a daily total and converted at 2.07 mol of PAR per MJ. The sky over the habitat, measured; what reaches a plant under a rock, a shrub or a shade cloth is not.

Temperature. NASA POWER daily minima and maxima over 44 years at a typical spot in the range, lapse-corrected -121 m to its elevation; CHELSA monthly means, median year across the grid cells of the range. The cold floor is the 1st-percentile night named in its sentence. Not a measured survival limit for any plant in a pot.

Humidity. CHELSA relative humidity, median year across the grid cells of the range.

Group. Listed under the family Liliaceae in the archetype table, and Kew describes it as “bulbous geophyte”. A group is taken only where Kew's description of the species agrees with the table's listing. The table gives no figure and no prose; the cold floor is the habitat's alone.

Climate across the habitat

Habitat months, northern hemisphere

Habitat climate of Erythronium americanum through the yearWarmest month July, mean daily high 26 °C; coldest month January, mean nightly low -8.1 °C; 1,116 mm of rain in the median year (the twelve monthly medians added). Medians across the range, from CHELSA; the extremes at the edge from NASA POWER. Habitat months, northern hemisphere.-40°-20°0°20°40°frost32.5° 99th-percentile day, NASA POWER-27.9° lowest night in 44 years, NASA POWER°C · day and nightcold quarter0255075100125150mm rainDLI 9–39RH 56–61%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 1361 habitat cells, CHELSA cold quarter: the three months around the coldest month's mean nightly low extremes over 44 years at a typical spot in the range, from NASA POWER, marked at the edge, in no month DLI, mol/m²/dayRH %each on its own scale
Figures by month
JanFebMarAprMayJunJulAugSepOctNovDec
Day °C-1 / -5–51 / -3–76 / 2–1213 / 9–1819 / 16–2324 / 21–2826 / 24–3025 / 23–2921 / 19–2515 / 12–198 / 5–132 / -2–7
Night °C-8 / -14–-3-7 / -13–-2-3 / -7–23 / 0–79 / 7–1315 / 12–1818 / 15–2017 / 15–2013 / 11–167 / 4–102 / -1–5-4 / -9–-1
Rain mm78 / 58–9971 / 52–9683 / 57–11492 / 73–116103 / 84–126106 / 84–126108 / 84–13496 / 83–121100 / 85–12196 / 74–12594 / 77–11989 / 66–116
DLI12 / 10–1418 / 17–2026 / 24–2732 / 30–3437 / 35–3839 / 37–4138 / 37–4034 / 32–3526 / 24–2918 / 16–2212 / 9–159 / 8–12
RH %61 / 57–6559 / 56–6357 / 55–6056 / 55–5857 / 56–5959 / 57–6159 / 57–6160 / 58–6260 / 58–6259 / 57–6260 / 58–6361 / 57–65
How this section is made
Each figure is the median across the 1361 grid cells on land that hold in-range records (1719 records in those cells; 2 more cells hold records but no land by the elevation layer, so those records sit at sea and the cells are left out), with the 10th–90th percentile span across those cells after the slash where it differs. A dash is a month one or more of those cells has no figure for in the grid (a variable CHELSA does not carry there), so no median is taken rather than one over fewer cells. Extremes and elevation were read at a typical spot in the range, cell 968:2085 (41.575, -75.725). Over 44 years there: absolute minimum -27.9 °C, 1st-percentile night -17.8 °C, 99th-percentile day 32.5 °C. Normals: CHELSA V2.1 1981–2010 climatology, 0.05° cells (each the mean of ~36 1 km pixels). Across the range: median and 10th–90th percentile of each month across the 1361 distinct grid cells holding 1719 of the 1721 in-range records (2 further cells with records at sea, by the elevation layer, left out); extremes and elevation at the typical cell 968:2085 (its coldest month's mean nightly low nearest the median across cells); its position is the cell centre. Extremes: NASA POWER (MERRA-2) daily 1981–2024, cell 41.50_-75.625, lapse-corrected -121 m at 6.5 °C/km. Elevation: ETOPO 2022, 344 m (cell mean).

Natural habitat

Native range as published by WCVP; the marker is where the records are densest and decides nothing: the climate was read across the cells of the in-range records placed well enough to read one, not at the marker.
Openly licensed records inside the range, framed on where they fall.
NativeLabrador, New Brunswick, Newfoundland, Nova Scotia, Ontario, Québec, Illinois, Iowa, Minnesota, Missouri, Wisconsin, Connecticut, Indiana, Maine, Massachusetts, Michigan, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode I., Vermont, West Virginia, Alabama, Delaware, Georgia, Kentucky, Maryland, Mississippi, North Carolina, South Carolina, Tennessee, Virginia · regions are the level-3 units of the World Geographical Scheme for Recording Plant Distributions, as Kew's World Checklist records ranges, some under historical names such as Yugoslavia or Czechoslovakia (how).
Map marker41.019, -74.13 · in the densest population, 1407 records (75% of those in range)
Kew's description“bulbous geophyte” · “temperate” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 1876 georeferenced records inside the native range; the climate across the range on the 1719 of them in the land cells it reads, of 1721 placed to within 10 km; the map shows only the 389 openly licensed ones, which alone would put the marker 58 km away. 4 records outside the WCVP native range not used. 155 in-range records are placed to worse than 10 km, or with no stated accuracy (admitted only as a person's observation to three decimals), and stay on the map but off the climate.
Other GBIF keysRecords also from GBIF's key 11319317 (Erythronium americanum KerGawl.): Kew's file holds it as Erythronium americanum Ker Gawl. (accepted); 9 records, from GBIF's search API on the day of the build.
How this section is made
The map marker: the openly licensed record nearest the middle of the densest 1° population inside the densest 4° block of the 1876 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Erythronium americanum, photograph 1did not loadErythronium americanum, photograph 2did not loadErythronium americanum, photograph 3did not loadErythronium americanum, photograph 4did not loadErythronium americanum, photograph 5did not loadErythronium americanum, photograph 6did not load

Photographs: (c) Patrick Jackson, some rights reserved (CC BY); (c) Alex Novarro, some rights reserved (CC BY); (c) Jensyn Scott, some rights reserved (CC BY); author not stated, no rights reserved · CC0; (c) Cy Stavros, some rights reserved (CC BY); (c) Loïc Mathieu, some rights reserved (CC BY).

Similar habitat climate The 6 nearest by mean daily high, mean nightly low and rain, month by month. How.

Fraxinus americana Fraxinus americana White ash Photo: CC BY, Zihao WangCrataegus coccinea Crataegus coccinea Scarlet hawthorn Photo: CC0, author not statedCrataegus macrosperma Crataegus macrosperma Variable hawthorn Photo: CC BY, Micki ColbeckCarex tonsa Carex tonsa Shaved sedge Photo: CC BY, Dustin SniderOstrya virginiana Ostrya virginiana Eastern hop-hornbeam Photo: CC0, author not statedRhus typhina Rhus typhina Staghorn sumac Photo: CC BY, christine123

Other Erythronium 28 in the reference

Erythronium albidum Erythronium albidum White trout lily Photo: CC0, author not statedErythronium californicum Erythronium californicum California fawn-lily Photo: CC BY, gretchenparadisErythronium caucasicum Erythronium caucasicum Caucasian Dog's Tooth Violet Photo: CC BY, Виктория БилоусErythronium citrinum Erythronium citrinum Cream Fawn Lily Photo: CC BY, Dee Shea HimesErythronium dens-canis Erythronium dens-canis Dog's-tooth-violet Photo: CC BY, Barry StewartErythronium elegans Erythronium elegans Coast Range Fawn-lily Photo: CC BY, Dee Shea HimesErythronium grandiflorum Erythronium grandiflorum Glacier lily Photo: CC BY, Cody HinchliffErythronium helenae Erythronium helenae Pacific fawnlily Photo: CC BY, Ken-ichi UedaErythronium hendersonii Erythronium hendersonii Henderson's fawn-lily Photo: CC BY, Dee Shea HimesErythronium howellii Erythronium howellii Howell's fawn lily Photo: CC BY, Trevor Van LoonErythronium idahoense Erythronium idahoense Liliaceae Photo: CC BY, Charles SwiftErythronium japonicum Erythronium japonicum Asian fawnlily Photo: CC BY, yajapin all 29 ›

Names & registers

Also known as Erythronium americanum f. americanum; Erythronium flavum. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Liliaceae
Described by
Ker Gawl.
Native to
Labrador, New Brunswick, Newfoundland +31
Wild records
1876 in range · 389 open

Every figure here is derived from public data by a stated rule and names its source; nothing about this species is written for its page by a person or by AI, apart from the marked, credited quotations. How →

Where this page came from built 2026-10-22
GBIF species record gbif.species answeredasked 2026-10-22
GBIF synonyms gbif.synonyms answeredasked 2026-10-22
GBIF common names gbif.vernacular answeredasked 2026-10-22names fetched 2026-10-22
WCVP native range wcvp.distribution answeredas of 2026-06-04
GBIF occurrence records gbif.occurrences answeredasked 2026-10-22GBIF occurrence download https://doi.org/10.15468/dl.hbdw64, of 2026-10-21; 9 records of GBIF's key 11319317, Erythronium americanum KerGawl. (Kew's file holds it as Erythronium americanum Ker Gawl. (accepted)): GBIF occurrence search API; 73 records within 1 km of a botanic garden, herbarium or zoo left out (69 at a botanic garden or arboretum, 2 at a herbarium, 2 at a zoo; Wikidata's list)
Habitat climate climate answeredasked 2026-10-22
Daily extremes (NASA POWER) climate.extremes answeredasked 2026-10-22NASA POWER (MERRA-2) daily 1981–2024, cell 41.50_-75.625, lapse-corrected -121 m at 6.5 °C/km
Wikidata wikidata answeredasked 2026-10-22
Wikipedia wikipedia answeredasked 2026-10-22
iNaturalist photographs, wild inat.photos.wild answeredasked 2026-10-22from iNaturalist's open data of 2026-09-27: research-grade observations with an open-licence photograph, the 24 whose photographs iNaturalist received last (the open data holds no votes); filled 2026-10-22
iNaturalist photographs, cultivated inat.photos.cultivated not asked
GBIF media gbif.media answeredasked 2026-10-22
OpenAlex papers openalex not askednot yet asked for this reference; a later fill takes the papers from OpenAlex's snapshot

Every source is recorded as having answered, reported nothing, refused, failed, not been asked, or answered twice where one answer is taken (“not taken: two items answered”), and, for a source asked when this page was built, when: the figures are as the source held them that day; a source read from a file (Kew's World Checklist, a GBIF download) says "as of" the file's day instead; a row carried from an earlier build of the page names that build instead. Only “nothing to report” is ever shown as an absence. Records came from 46 datasets via GBIF.org; each carries its own licence.

Cultifolio

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