




24 photographs › At a glance
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- Oct, shaded
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- Dec, shaded
About the genus · Viola
The viola ( vee-OH-lə, Italian: [ˈvjɔːla, viˈɔːla]) is a string instrument of the violin family, and is usually bowed when played. The viola is slightly larger than the violin and has a lower sound. Since the 18th century, it has been the middle or alto voice of the violin family, between the violin (which is tuned a perfect fifth higher) and the cello (which is tuned an octave lower). More on Wikipedia ›
Quoted from Wikipedia, "Viola", CC BY-SA 4.0.
Cultivation
Seasons
The rain rule reads a winter growing season: 70% of the median year's rain (324 mm of 453 mm) falls in October to February, cooler than the year (wet-season mean 18.1 °C against a yearly mean of 18.9 °C). Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: April to August.
Rain
453 mm in the median year at the habitat, 324 mm of it October to February. Wettest month November at 74 mm, driest months (2 at 5 mm). Across the grid cells of the range the year's total runs 408 mm to 475 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 451 mm, is the year's rain at the top of the page; the 453 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: 22 to 47 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 18, the highest 90th-percentile month 47).
Warmth and air
Monthly means: the coldest month's mean nightly low 15.6 °C in February (across the grid cells of the range 14.3 °C to 16.3 °C), the warmest month's mean daily high 22.6 °C in August (median year across the grid cells of the range, CHELSA). Cold floor: none read. The nearest figure is 15.6 °C, the coldest month's mean nightly low, February, in the median year (CHELSA); a month's mean of its nightly lows is warmer than the nights a floor is read from. The daily extremes were read at a weather cell that is mostly sea and are not used.
Relative humidity at the habitat: 61 to 67% 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. CHELSA monthly means, median year across the grid cells of the range. No cold floor is read without a daily extremes series; the coldest month's mean nightly low named in its sentence is not one. 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 17 °C in Jan, Feb, Mar and Apr to 23 °C in Aug; mean nightly low from 16 °C in Jan, Feb, Mar and Apr to 22 °C in Aug. The cold quarter, Jan to Mar, is the three months around the coldest month's mean nightly low, centred on the 4 months in a row that tie for it. 453 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 6 habitat cells. 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 | 17 / 16–18 | 17 / 16–17 | 17 / 16–18 | 17 / 16–18 | 18 / 18–19 | 20 / 20–20 | 22 / 21–22 | 23 / 22–23 | 22 / 22–23 | 21 / 20–22 | 20 / 18–21 | 18 / 17–19 |
| Night °C | 16 / 15–17 | 16 / 14–16 | 16 / 15–16 | 16 / 15–17 | 17 / 17–18 | 19 / 19–19 | 21 / 20–21 | 22 / 21–22 | 21 / 21–22 | 20 / 19–21 | 19 / 17–19 | 17 / 16–18 |
| Rain mm | 64 / 57–67 | 60 / 54–63 | 51 / 47–55 | 30 / 28–32 | 14 / 13–15 | 8 / 7–8 | 5 / 4–5 | 5 / 5–6 | 16 / 15–18 | 53 / 48–56 | 74 / 66–77 | 73 / 65–75 |
| DLI | 24 / 20–25 | 30 / 26–30 | 37 / 34–38 | 42 / 40–42 | 45 / 45–46 | 47 / 46–47 | 45 / 45–46 | 43 / 42–44 | 39 / 36–39 | 32 / 29–33 | 25 / 22–26 | 22 / 18–23 |
| RH % | 61 / 60–63 | 62 / 62–64 | 63 / 62–63 | 63 / 61–67 | 64 / 62–67 | 67 / 64–68 | 67 / 64–68 | 67 / 64–68 | 66 / 64–67 | 65 / 63–67 | 62 / 62–64 | 62 / 61–64 |
The daily extremes were read at a NASA POWER cell that is 36% land: neither it nor the next candidates whose coldest month's mean nightly low is within 2 °C of the median across cells sit in a POWER cell that is mostly land, and the rule reads a cold floor only from a cell that is mostly land, so none is read for this species. Nor is the coldest month's mean nightly low taken as one: it is a mean of a month's lows, not its coldest night. What that cell gave over 44 years: absolute minimum 12.4 °C, 1st-percentile night 14.0 °C, 99th-percentile day 25.9 °C.
How this section is made
Natural habitat
How this section is made
Photographs
Photographs: Phill Robinson, CC BY, iNaturalist via GBIF; Christoph Moning, CC BY, iNaturalist via GBIF; Diego Rodríguez Hernández, CC BY, iNaturalist via GBIF (3); Alessia Guggisberg, CC BY, iNaturalist via GBIF.
Related
Similar habitat climate The 6 nearest by mean daily high, mean nightly low and rain, month by month. How.
Sideritis macrostachyos Lamiaceae Photo: CC BY, Enrico Tomschke
Monanthes anagensis Crassulaceae Photo: CC BY, Ben Jobson Lotus dumetorum Fabaceae
Gonospermum revolutum Asteraceae Photo: CC BY, Pablo MR
Limonium macrophyllum Plumbaginaceae Photo: CC BY, Ben Jobson
Pterocephalus virens Caprifoliaceae Photo: CC BY, Ben JobsonOther Viola 138 in the reference
Viola acuminata Long-stem violet Photo: CC0, author not stated
Viola adunca Blue violet Photo: CC BY, Syd Cannings
Viola alba Parma violet Photo: CC BY, Илья Руденко
Viola albida Taebaek violet Photo: CC0, author not stated
Viola alpina Violaceae Photo: CC BY-SA, xulescu_g
Viola altaica Altaic Violet Photo: CC BY, b166er
Viola arborescens Shrubby Violet Photo: CC BY, Teo Albert
Viola arvensis Field pansy Photo: CC0, author not stated
Viola atropurpurea Violaceae Photo: CC BY-SA, Grzegorz Grzejszczak
Viola bakeri Baker's violet Photo: CC BY, Gail A Baker
Viola banksii Australian Native Violet Photo: CC0, author not stated
Viola beckwithii Beckwith's violet Photo: CC BY, Steve Matson all 139 ›Names & registers
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 answeredas of 2026-10-21GBIF occurrence download https://doi.org/10.15468/dl.hbdw64, of 2026-10-21climate answeredasked 2026-10-22climate.extremes answeredasked 2026-10-22NASA POWER (MERRA-2) daily 1981–2024, cell 28.50_-16.250, lapse-corrected +67 m at 6.5 °C/km; read, and set aside: NASA POWER's cell is mostly sea (36% land), so no cold floor is shownwikidata answeredasked 2026-10-22wikipedia nothing to reportasked 2026-10-22inat.taxon not askedinat.photos.wild not askedinat.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 10 datasets via GBIF.org; each carries its own licence.






