




70 photographs › At a glance
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Summary
Thalictrum flavum, known by the common names common meadow-rue, poor man's rhubarb, and yellow meadow-rue, is a flowering plant species in the family Ranunculaceae. Its native range covers temperate regions of Eurasia and North Africa. Growing to 100 cm (39 in) tall by 45 cm (18 in) broad, it is an herbaceous perennial producing clusters of fluffy yellow fragrant flowers in summer.
Quoted from Wikipedia, "Thalictrum flavum", CC BY-SA 4.0.
About the genus · Thalictrum
Thalictrum is a genus of 120–200 species of herbaceous perennial flowering plants in the buttercup family, Ranunculaceae, native mostly to temperate regions. Meadow-rue is a common name for plants in this genus.
Quoted from Wikipedia, "Thalictrum", CC BY-SA 4.0.
Cultivation
Seasons
The rain rule reads no short rainy season: 70% of the median year's rain (620 mm of 861 mm) takes 8 months, June to January. Mean temperature moves 15.2 °C between the warmest and coldest month. Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: December to July.
Rain
861 mm in the median year at the habitat, 620 mm of it June to January. Wettest month November at 81 mm, driest month April at 47 mm. Across the grid cells of the range the year's total runs 659 mm to 960 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 873 mm, is the year's rain at the top of the page; the 861 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: 4 to 33 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 2, the highest 90th-percentile month 37).
Warmth and air
Coldest: the 1st-percentile night over 44 years at a typical spot in the range is -9.2 °C, the absolute minimum -21.8 °C, 2,806 frost nights in 44 years, 63.8 a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 29.7 °C. Monthly means: the coldest month's mean nightly low 0.4 °C in January and February (across the grid cells of the range -4.0 °C to 1.4 °C), the warmest month's mean daily high 21.9 °C in July (median year across the grid cells of the range, CHELSA). Cold floor: -9.2 °C, which is the 1st-percentile night over 44 years at a typical spot in the range (NASA POWER).
Relative humidity at the habitat: 59 to 69% 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 -18 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.
Climate across the habitat
Habitat months, northern hemisphere
Mean daily high from 5 °C in Jan to 22 °C in Jul and Aug; mean nightly low from 0 °C in Jan and Feb to 14 °C in Jul and Aug. The cold quarter, Dec to Feb, is the three months around the coldest month's mean nightly low, centred on the 2 months in a row that tie for it. 861 mm of rain in the median year (the twelve monthly medians added), the wettest month Nov. The bands show the 10th to 90th percentile across 330 habitat cells. Over 44 years at a typical spot in the range (NASA POWER) the absolute minimum was -21.8 °C and the 99th-percentile day 29.7 °C; neither is dated to a month. Beneath: daily light integral and relative humidity through the year, each on its own scale.
Figures by month
| Figure | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Day °C | 5 / 1–6 | 6 / 1–7 | 10 / 4–10 | 13 / 10–14 | 17 / 14–18 | 20 / 18–21 | 22 / 20–23 | 22 / 20–23 | 18 / 15–19 | 14 / 11–15 | 9 / 5–10 | 6 / 2–6 |
| Night °C | 0 / -4–1 | 0 / -4–1 | 3 / -2–3 | 5 / 2–5 | 9 / 7–9 | 11 / 10–12 | 14 / 13–15 | 14 / 13–15 | 11 / 10–12 | 8 / 6–9 | 4 / 1–5 | 1 / -3–2 |
| Rain mm | 76 / 51–84 | 60 / 40–65 | 69 / 44–76 | 47 / 38–58 | 65 / 51–73 | 72 / 62–84 | 80 / 64–92 | 76 / 64–94 | 75 / 59–92 | 80 / 63–103 | 81 / 60–94 | 80 / 55–90 |
| DLI | 5 / 3–6 | 10 / 8–11 | 17 / 15–20 | 27 / 25–29 | 32 / 32–35 | 33 / 33–37 | 32 / 32–36 | 27 / 27–30 | 19 / 18–21 | 11 / 10–13 | 6 / 4–7 | 4 / 2–5 |
| RH % | 68 / 66–69 | 65 / 64–67 | 63 / 62–64 | 60 / 59–62 | 59 / 58–61 | 60 / 58–62 | 61 / 59–62 | 61 / 60–62 | 63 / 62–64 | 65 / 64–66 | 68 / 66–69 | 69 / 67–70 |
How this section is made
Natural habitat
How this section is made
Photographs
Photographs: (c) Oleg Kosterin, some rights reserved (CC BY) (6).
Related
Similar habitat climate The 6 nearest by mean daily high, mean nightly low and rain, month by month. How.
Myosotis scorpioides True forget-me-not Photo: CC0, author not stated
Nuphar lutea Yellow water-lily Photo: CC BY, Мирослав Соболев
Valeriana officinalis Common valerian Photo: CC0, author not stated
Equisetum palustre Marsh horsetail Photo: CC BY, Stephan Mende
Alisma plantago-aquatica European water plantain Photo: CC BY, Мирослав Соболев
Centaurea jacea Brown knapweed Photo: CC BY, Jason GrantOther Thalictrum 46 in the reference
Thalictrum actaeifolium Twinkling-star Photo: CC BY, Kim, Hyun-tae
Thalictrum alpinum Alpine meadow-rue Photo: CC BY, Ingvild Riska
Thalictrum aquilegiifolium French meadow-rue Photo: CC BY, Dmitriy Bochkov
Thalictrum baicalense Baical meadow-rue Photo: CC0, Фёдор Thalictrum calabricum Ranunculaceae
Thalictrum clavatum Mountain meadow-rue Photo: CC0, author not stated
Thalictrum cooleyi Cooley's meadow-rue Photo: CC0, author not stated
Thalictrum coriaceum Maid of the mist Photo: CC BY, Michael J. Papay
Thalictrum cultratum Ranunculaceae Photo: CC BY, Siddarth Machado
Thalictrum dasycarpum Purple meadow-rue Photo: CC0, author not stated all 47 ›Names & registers
Also known as Thalictrum altissimum; Thalictrum angustifolium subsp. mediterraneum; Thalictrum angustifolium var. flavum; Thalictrum angustifolium var. mediterraneum; Thalictrum angustifolium var. morisonii and 67 more. (GBIF Backbone)
Kew accepts as species of their own Thalictrum morisonii: older names in GBIF's record of this species that Kew's World Checklist accepts as other species. (WCVP, RBG Kew, file of 2026-06-04)
The record
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 answeredasked 2026-10-22gbif.synonyms answeredasked 2026-10-22gbif.vernacular answeredasked 2026-10-22names fetched 2026-10-22wcvp.distribution answeredas of 2026-06-04gbif.occurrences answeredasked 2026-10-22GBIF occurrence search API; 15 records within 1 km of a botanic garden, herbarium or zoo left out (2 at a botanic garden or arboretum, 13 at a zoo; Wikidata's list)climate answeredasked 2026-10-22climate.extremes answeredasked 2026-10-22NASA POWER (MERRA-2) daily 1981–2024, cell 51.50_6.250, lapse-corrected -18 m at 6.5 °C/kmwikidata answeredasked 2026-10-22wikipedia answeredasked 2026-10-22inat.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 2026-10-22inat.photos.cultivated not askedgbif.media answeredasked 2026-10-22openalex not askednot yet asked for this reference; a later fill takes the papers from OpenAlex's snapshotEvery 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 12 datasets via GBIF.org; each carries its own licence.






