Allium cernuum Roth
lady's leek, nodding onion, nodding pink onion, nodding wild onion
Every figure on this page is derived from public data by a stated rule and says its source; nothing here is written by a person or a model, except the Wikipedia passage, which is quoted and marked as such. How it is made.
Summary
Allium cernuum, known as nodding onion or lady's leek, is a perennial plant in the genus Allium. It grows in open areas in North America.
Text from Wikipedia, “Allium cernuum”, CC BY-SA 4.0, quoted as written. Kept separate from everything derived here.
About the genus · Allium
Allium is a large genus of monocotyledonous flowering plants with 1112 accepted species, making Allium the largest genus in the family Amaryllidaceae and among the largest plant genera in the world. Many of the species are edible, and some have a long history of cultivation and human consumption such as the onion, garlic, scallions, shallots, leeks, and chives.
Text from Wikipedia, “Allium”, CC BY-SA 4.0, quoted as written.
At a glance
Also known as Allium alatum Schreb.; Allium alatum Schreb. ex Roth; Allium allegheniense Small; Allium cernuum f. alba J.K.Henry; Allium cernuum f. obtusum Cockerell and 17 more.
Cultivation
Grouped as a bulb, tuber or caudex by Amaryllidaceae, which is usually but not always one kind of plant (archetype table). The table holds no figure for this group, which spans too much for one minimum; the cold floor is the habitat's alone, and no prose comes from the table.
Its year Rain rule: no season, 70% of the rain takes 8 months (April to November in the northern hemisphere).
This species’ habitat figures, and what two fixed rules read from them.
The rain rule reads no season: 70% of the year's rain (524 mm of 704 mm) takes 8 months, April to November. Mean temperature moves 22.6 °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.
Read from the median year of CHELSA monthly rainfall and mean temperature across the envelope cells: 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 gives a season to reverse. A reading of the curves, not an observation of the plant.
Rain Habitat rain 704 mm a year, wettest June at 77 mm, driest February at 38 mm (habitat calendar, northern hemisphere).
This species’ habitat figures, with their source.
704 mm a year at the habitat, 524 mm of it April to November. Wettest month June at 77 mm, driest February at 38 mm. Across the envelope cells the year's total runs 419 mm to 1381 mm (10th to 90th percentile of each cell's own year) (median year across the envelope cells, CHELSA; habitat calendar, northern hemisphere).
CHELSA monthly precipitation, median year across the envelope cells. The rain that falls where the species is recorded; nothing about how the plant takes water.
Light Open sky over the habitat: 10 to 43 mol/m²/day.
This species’ habitat figures, with their source.
Open sky over the habitat: 10 to 43 mol/m²/day across the year (daily light integral, median year across the envelope cells, CHELSA; the lowest 10th-percentile month across the cells is 5, the highest 90th-percentile month 51).
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.
Warmth and air Cold floor -16.9 °C (1st-percentile habitat night, NASA POWER).
This species’ habitat figures, with their source.
Coldest: the 1st-percentile night over 44 years at the typical cell is -16.9 °C, the absolute minimum -27.4 °C, about 173 frost nights a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 33.2 °C. Monthly means: coldest night -8.6 °C in January (across the envelope cells -13.9 °C to 1.2 °C), warmest day 25.0 °C in July (median year across the envelope cells, CHELSA). Cold floor: -16.9 °C, which is the 1st-percentile night over 44 years at the typical cell (NASA POWER).
NASA POWER daily minima and maxima 1981–2024 at the typical cell, lapse-corrected to its elevation; CHELSA monthly means, median year across the envelope cells, CHELSA. The cold floor is the figure named in its sentence. Not a measured survival limit for any plant in a pot.
Relative humidity at the habitat: 54 to 61% across the year (monthly means, median year across the envelope cells, CHELSA). A figure about the air, saying nothing about how the plant takes water.
CHELSA relative humidity, median year across the envelope cells.
The figures the cards read from are in Climate below, and where they came from in Natural habitat.
Climate across the habitat
Figures by month
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Day °C | 0 / -5–7 | 3 / -2–8 | 7 / 2–12 | 12 / 6–17 | 17 / 11–22 | 22 / 16–27 | 25 / 19–29 | 24 / 19–28 | 20 / 15–24 | 14 / 8–18 | 7 / -0–12 | 1 / -6–7 |
| Night °C | -9 / -14–1 | -7 / -13–2 | -3 / -9–4 | 1 / -5–7 | 5 / -1–11 | 10 / 4–17 | 13 / 7–19 | 13 / 7–19 | 9 / 3–15 | 3 / -3–10 | -3 / -10–5 | -8 / -14–2 |
| Rain mm | 42 / 16–146 | 38 / 16–119 | 51 / 23–120 | 58 / 24–109 | 72 / 30–126 | 77 / 30–125 | 75 / 31–118 | 76 / 31–117 | 57 / 35–100 | 54 / 29–112 | 55 / 19–162 | 49 / 18–150 |
| DLI | 12 / 7–22 | 19 / 13–28 | 26 / 20–37 | 34 / 30–45 | 40 / 36–49 | 42 / 39–51 | 43 / 39–47 | 37 / 34–42 | 28 / 26–38 | 20 / 15–30 | 13 / 7–23 | 10 / 5–19 |
| RH % | 61 / 51–67 | 59 / 51–63 | 57 / 50–62 | 55 / 46–60 | 55 / 45–60 | 55 / 44–60 | 54 / 49–60 | 55 / 50–60 | 56 / 50–61 | 57 / 49–63 | 59 / 49–66 | 61 / 51–67 |
Each figure is the median across the 1333 grid cells holding the 1812 in-range records, with the 10th–90th percentile span across those cells after the slash where it differs. Extremes and elevation were read at the typical cell 1042:1367 (37.875, -111.625). Over 44 years there: absolute minimum -27.4 °C, 1st-percentile night -16.9 °C, 99th-percentile day 33.2 °C. Normals: CHELSA V2.1 1981–2010 climatology, 0.05° cells (each the mean of ~36 1 km pixels). Envelope: median and 10th–90th percentile of each month across the 1333 distinct grid cells holding the 1812 in-range records; extremes and elevation at the typical cell 1042:1367 (its coldest month's mean night nearest the median across cells); its position is the cell centre. Extremes: NASA POWER (MERRA-2) daily 1981–2024, cell 38.00_-111.875, lapse-corrected -234 m at 6.5 °C/km. Elevation: ETOPO 2022, 2217 m (cell mean).
Natural habitat
Photographs
Photographs: no rights reserved · CC0 (5); (c) Peyton Phelps, some rights reserved (CC BY) (3).
Photographs: iNaturalist did not answer when this page was built; what is shown came from the sources that did.
Papers naming this species
Works whose title or abstract names Allium cernuum, most cited first, from OpenAlex (CC0). A mention, not a cultivation source: nothing on this page is drawn from them.
Related
Similar habitat climate the 6 species whose habitat climate is nearest this one's: mean day and night, month by month, and rain on a log scale, in calendar order, so a habitat with the same seasons six months out is far, not near. Nothing else counts: not range, not family.
Colchicum trigynum Colchicaceae
Maianthemum stellatum False Solomon's Seal
Rosa woodsii Prairie Rose
Psephellus dealbatus Persian Cornflower
Arctostaphylos uva-ursi Bear-grape
Scilla buekkensis AsparagaceaeOther Allium 12 in the reference
Allium ampeloprasum Broadleaf Wild Leek
Allium cepa Garden onion
Allium cristophii Persian onion
Allium fistulosum Japanese bunching onion
Allium moly Lily Leek
Allium sativum Cultivated Garlic
Allium schoenoprasum Chives
Allium siculum Honey Garlic
Allium sphaerocephalon Round-Headed Leek
Allium triquetrum Angled Onion
Allium tuberosum Chinese Chives
Allium ursinum Amaryllidaceae History & registers
Where this page came from built 2026-09-20 · dossier v2 · node
gbif.species answeredcarried from build of 2026-09-20 (offline re-derivation; the backbone was not asked)gbif.synonyms answeredcarried from build of 2026-09-20 (offline re-derivation; the backbone was not asked)gbif.vernacular answeredcarried from build of 2026-09-20 (offline re-derivation; the backbone was not asked)wcvp.distribution answeredgbif.occurrences answeredGBIF occurrence download https://doi.org/10.15468/dl.3h4zamclimate answeredwikidata answeredcarried from build of 2026-09-20 (rederive); that build: carried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)wikipedia answeredcarried from build of 2026-09-20; this build: skippedinat.taxon not askedcarried from build of 2026-09-20 (rederive)inat.photos.wild answeredcarried from build of 2026-09-20; this build: skippedinat.photos.cultivated nothing to reportcarried from build of 2026-09-20 (rederive); that build: carried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)commons nothing to reportcarried from build of 2026-09-20 (rederive); that build: carried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)gbif.media answeredopenalex answeredcarried from build of 2026-09-20; this build: skippedEvery upstream is recorded as having answered, reported nothing, or refused. Only “nothing to report” is ever shown as an absence. Records came from 83 datasets via GBIF.org; each carries its own licence.