Species
+

Geranium phaeum L.

Bruna pyskawa, Dusky Crane's-Bill, Mourning Widow, black widow

Climate known 51 photographs Temperate garden plant
Add one to my plants Sow seed

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

Geranium phaeum, commonly called dusky crane's-bill, mourning widow or black widow, is a herbaceous plant species in the family Geraniaceae. It is native to southern, central, and western Europe, and is cultivated as a garden subject. It has dark violet colored flowers. It is unmistakable with dark purple petals turned backwards and with conspicuous projecting stamens and style. More on Wikipedia ›

The opening of Wikipedia, “Geranium phaeum”, CC BY-SA 4.0, quoted as written. Kept separate from everything derived here.

About the genus · Geranium

Geranium is a genus of 422 species of annual, biennial, and perennial plants that are commonly known as geraniums, hardy geraniums, or cranesbills. They are found throughout the temperate regions of the world and the mountains of the tropics, with the greatest diversity in the eastern part of the Mediterranean region.

Text from Wikipedia, “Geranium”, CC BY-SA 4.0, quoted as written.

Family
Geraniaceae
Described by
L.
Native to
Austria, Czechoslovakia, Germany +13
Wild records
1371 in range· 894 open

At a glance

Warmest month
22°C
Jul, mean day; nights 13 °C (CHELSA)
Rain
1029mm/yr
12 wet months · peak Jun 107 mm (CHELSA)
Light
6–35DLI
mol/m²/day, winter to summer, open sky (CHELSA shortwave)
In short condensed by rule from the cultivation cards · not written by a person
Grouped as a temperate garden plant by the genus Geranium, which is reliably one kind of plant (archetype table). Rain rule: no season, 70% of the rain takes 8 months (May to December in the northern hemisphere). Habitat rain 1029 mm a year, wettest June at 107 mm, driest February at 60 mm (habitat calendar, northern hemisphere). Open sky over the habitat: 6 to 35 mol/m²/day. Cold floor -13.3 °C (1st-percentile habitat night, NASA POWER).
Each sentence is one card's own one-line form, written by the same rule as the card (Its year, Rain, Light, Temperature); the note cannot say what a card does not. Months are given for the northern hemisphere (set your site in Settings to change this), and the habitat's own alongside. The cards · the figures.

Also known as Geranium austriacum Wiesb. ex Hayek; Geranium austriacum Wiesb., 1901; Geranium fuscum L.; Geranium hungaricum Wiesb.; Geranium hungaricum Wiesb. ex Grecescu and 45 more.

Cultivation

Grouped as a temperate garden plant by the genus Geranium, which is reliably 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 (May to December 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 (746 mm of 1029 mm) takes 8 months, May to December. Mean temperature moves 18.9 °C between the warmest and coldest month. Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: November to June.

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 1029 mm a year, wettest June at 107 mm, driest February at 60 mm (habitat calendar, northern hemisphere).

This species’ habitat figures, with their source.

1029 mm a year at the habitat, 746 mm of it May to December. Wettest month June at 107 mm, driest February at 60 mm. Across the envelope cells the year's total runs 738 mm to 1723 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: 6 to 35 mol/m²/day.

This species’ habitat figures, with their source.

Open sky over the habitat: 6 to 35 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 4, the highest 90th-percentile month 40).

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 -13.3 °C (1st-percentile habitat night, NASA POWER).

This species’ habitat figures, with their source.

Temperature

Coldest: the 1st-percentile night over 44 years at the typical cell is -13.3 °C, the absolute minimum -25.1 °C, about 105 frost nights a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 27.7 °C. Monthly means: coldest night -5.0 °C in January (across the envelope cells -9.9 °C to 0.5 °C), warmest day 21.7 °C in July (median year across the envelope cells, CHELSA). Cold floor: -13.3 °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.

Humidity

Relative humidity at the habitat: 60 to 66% 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

Habitat climate through the yearMean day from 2 °C in Jan to 22 °C in Jul; mean night from -5 °C in Jan to 13 °C in Jul. The cold quarter, Dec to Feb, is the three months around the coldest night. 1029 mm of rain a year, most in Jun. The bands show the 10th to 90th percentile across 1126 habitat cells. Over 44 years at the typical cell the absolute minimum was -25.1 °C and the 99th-percentile day 27.7 °C; neither is dated to a month. Beneath: daily light integral and relative humidity through the year, each on its own scale.-30°-20°-10°10°20°30°frost27.7° 99th-percentile day (undated)-25.1° lowest night in 44 yrs (undated)°C · day and nightcold quarter050100150200mm rainDLI 6–35RH 60–66 %JanFebMarAprMayJunJulAugSepOctNovDec
day night rain 10th–90th percentile across 1126 habitat cells cold quarter: the three months around the coldest night extremes over 44 years at the typical cell, marked at the edge: undated DLI, mol/m²/dayRH %each on its own scale
Figures by month
JanFebMarAprMayJunJulAugSepOctNovDec
Day °C2 / -2–64 / -1–78 / 3–1012 / 7–1417 / 12–1919 / 16–2222 / 18–2421 / 18–2418 / 14–2013 / 10–157 / 3–103 / -1–6
Night °C-5 / -10–1-4 / -9–1-1 / -6–33 / -3–58 / 2–911 / 6–1213 / 8–1513 / 8–159 / 5–115 / 1–80 / -5–4-3 / -9–1
Rain mm76 / 37–13460 / 36–11274 / 46–13173 / 45–140104 / 65–161107 / 74–174101 / 71–18597 / 73–17790 / 63–14983 / 50–15782 / 50–15382 / 48–156
DLI8 / 5–1214 / 10–1821 / 17–2629 / 27–3334 / 32–3635 / 33–3934 / 32–4030 / 27–3422 / 19–2715 / 11–199 / 6–126 / 4–10
RH %65 / 59–6963 / 59–6761 / 59–6460 / 58–6360 / 58–6361 / 59–6361 / 58–6361 / 58–6363 / 60–6564 / 61–6666 / 61–6966 / 60–70

Each figure is the median across the 1126 grid cells holding the 1364 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 851:3786 (47.425, 9.325). Over 44 years there: absolute minimum -25.1 °C, 1st-percentile night -13.3 °C, 99th-percentile day 27.7 °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 1126 distinct grid cells holding the 1364 in-range records; extremes and elevation at the typical cell 851:3786 (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 47.50_9.375, lapse-corrected -5 m at 6.5 °C/km. Elevation: ETOPO 2022, 704 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 every in-range record's cell, not at the marker.
Openly licensed records inside the range, framed on where they fall.
NativeAustria, Czechoslovakia, Germany, Hungary, Poland, Switzerland, France, Spain, Albania, Bulgaria, Italy, Romania, Yugoslavia, Belarus, Northwest European Russia, Ukraine· introduced: Denmark, Finland, Great Britain, Ireland, Sweden, Belgium, Netherlands, Baltic States, Central European Russia
Kew's description“perennial” · “temperate”· quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Map marker47.75, 14.23 · in the densest population, 323 records (24% of those in range)
Evidence usedThe map marker and the climate envelope rest on all 1371 georeferenced records inside the native range; the map shows only the 894 openly licensed ones, which alone would put the marker 11 km away. 369 records outside the range (gardens, roadsides, misidentifications) ignored. 7 in-range records are placed to worse than 10 km and stay on the map but off the climate.
The map markerthe map marker: the openly licensed record nearest the middle of the densest 1° population of the 1371 in-range records; it decides nothing.

Photographs

Geranium phaeumGeranium phaeumGeranium phaeumGeranium phaeumGeranium phaeumGeranium phaeumGeranium phaeumGeranium phaeum

Photographs: (c) Daniel Cahen, some rights reserved (CC BY) (4); no rights reserved · CC0; (c) Oleksandr Shynder, some rights reserved (CC BY); (c) Wolfgang Jauch, some rights reserved (CC BY) (2).

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 Geranium phaeum, most cited first, from OpenAlex (CC0). A mention, not a cultivation source: nothing on this page is drawn from them.

Contrasting Patterns of Nucleotide Substitution Rates Provide Insight into Dynamic Evolution of Plastid and Mitochondrial Genomes of Geranium
Seongjun Park, Tracey A. Ruhlman, Mao-Lun Weng, Nahid H. Hajrah (2017) · Genome Biology and Evolution
Chorological, ecological and taxonomic notes on the vascular flora of Hungary III
Gergely Király, Angéla Király (2018) · Botanikai Közlemények
Screening of selected plant extracts for in vitro inhibitory activity on HIV-1 reverse transcriptase (HIV-1 RT).
Aleš Mlinarič, Stefan G. Kreft, Andrej Umek, Borut Štrukelj (2000) · PubMed
A Comparative Study on Essential Oils of Geranium macrorrhizum L. and Geranium phaeum L., Geraniaceae from Serbia
Jean‐Claude Chalchat, Silvana Petrović, Zoran Maksimović, M. S. Gorunovic (2002) · Journal of Essential Oil Research
Phenolic Profiles and Cytotoxic Activities of Methanolic Extracts From Eight Geranium L. Species
Milan Ilić, Stevan Samardžić, Vesna Kojić, Dimitar Jakimov (2026) · Chemistry & Biodiversity
Occurrence Download
GBIF.Org User (2021) · Global Biodiversity Information Facility
The presumably North American species Plasmopara wilsonii is present in Germany on the ornamental plant Geranium phaeum
Julia Kruse, Marco Thines, Young‐Joon Choi (2016) · European Journal of Plant Pathology

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.

Other Geranium 7 in the reference

History & registers

Where this page came from built 2026-09-20 · dossier v2 · node
gbif.species answeredcarried from build of 2026-09-19 (offline re-derivation; the backbone was not asked)
gbif.synonyms answeredcarried from build of 2026-09-19 (offline re-derivation; the backbone was not asked)
gbif.vernacular answeredcarried from build of 2026-09-19 (offline re-derivation; the backbone was not asked)
wcvp.distribution answered
gbif.occurrences answeredGBIF occurrence download https://doi.org/10.15468/dl.3h4zam
climate answered
wikidata answeredcarried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
wikipedia answeredcarried from build of 2026-09-19; this build: skipped
inat.taxon not asked
inat.photos.wild answeredcarried from build of 2026-09-19; this build: skipped
inat.photos.cultivated nothing to reportcarried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
commons nothing to reportcarried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
gbif.media answered
openalex answeredcarried from build of 2026-09-19; this build: skipped

Every upstream is recorded as having answered, reported nothing, or refused. Only “nothing to report” is ever shown as an absence. Records came from 130 datasets via GBIF.org; each carries its own licence.