Alcea rosea L.
Black Hollyhock, Common hollyhock, Garten-Stockrose (DE); Hollyhock (EN), Hollyhock
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
Alcea rosea, the common hollyhock, is an ornamental dicot flowering plant in the family Malvaceae. It was imported into Europe from southwestern China during, or possibly before, the 15th century. William Turner, a herbalist of the time, gave it the name "holyoke" from which the English name derives.
Text from Wikipedia, “Alcea rosea”, CC BY-SA 4.0, quoted as written. Kept separate from everything derived here.
About the genus · Alcea
Alcea is a genus of over 80 species of flowering plants in the mallow family Malvaceae, commonly known as the hollyhocks. They are native to Asia and Europe. The single species of hollyhock from the Americas, the streambank wild hollyhock, belongs to a different genus.
Text from Wikipedia, “Alcea”, CC BY-SA 4.0, quoted as written.
At a glance
Also known as Alcea annua Winterl; Alcea cultorum Bergmans; Alcea ficifolia L.; Alcea ficifolia Nyman; Alcea ficifolia var. violacea Boiss. and 34 more.
Cultivation
Its year Rain rule: a winter growing season, October to January and March to May in the northern hemisphere (October to January and March to May at the habitat, northern).
This species’ habitat figures, and what two fixed rules read from them.
The rain rule reads a winter growing season: 70% of the year's rain (329 mm of 439 mm) falls in October to January and March to May, cooler than the year (wet-season mean 8.7 °C against a yearly mean of 12.9 °C). Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: April to July and September to November.
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 439 mm a year, wettest April at 56 mm, driest August at 10 mm (habitat calendar, northern hemisphere).
This species’ habitat figures, with their source.
439 mm a year at the habitat, 329 mm of it October to January and March to May. Wettest month April at 56 mm, driest August at 10 mm. Across the envelope cells the year's total runs 406 mm to 694 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: 13 to 46 mol/m²/day.
This species’ habitat figures, with their source.
Open sky over the habitat: 13 to 46 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 12, 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 -11.7 °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 -11.7 °C, the absolute minimum -21.0 °C, about 108 frost nights a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 36.5 °C. Monthly means: coldest night -3.6 °C in January (across the envelope cells -7.0 °C to 3.0 °C), warmest day 30.0 °C in July (median year across the envelope cells, CHELSA). Cold floor: -11.7 °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: 49 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 | 5 / 3–12 | 6 / 4–13 | 11 / 9–16 | 17 / 16–20 | 22 / 20–25 | 26 / 24–31 | 30 / 27–35 | 30 / 28–35 | 25 / 24–30 | 19 / 18–25 | 12 / 11–18 | 7 / 5–13 |
| Night °C | -4 / -7–3 | -3 / -6–4 | -0 / -1–6 | 5 / 4–11 | 10 / 8–16 | 14 / 12–20 | 17 / 15–23 | 17 / 16–23 | 13 / 12–20 | 8 / 7–16 | 2 / 1–9 | -2 / -4–5 |
| Rain mm | 43 / 35–118 | 37 / 33–109 | 44 / 37–90 | 56 / 52–78 | 53 / 33–66 | 33 / 6–48 | 14 / 1–25 | 10 / 1–17 | 16 / 9–21 | 38 / 33–42 | 46 / 39–103 | 49 / 38–117 |
| DLI | 15 / 14–17 | 22 / 21–23 | 30 / 28–31 | 37 / 34–38 | 42 / 40–46 | 46 / 43–51 | 46 / 43–50 | 42 / 39–46 | 34 / 31–37 | 24 / 21–27 | 17 / 15–18 | 13 / 12–15 |
| RH % | 60 / 55–61 | 58 / 55–59 | 55 / 54–58 | 54 / 51–58 | 53 / 48–58 | 50 / 44–56 | 49 / 42–55 | 49 / 43–54 | 49 / 44–55 | 53 / 49–58 | 58 / 54–60 | 61 / 56–61 |
Each figure is the median across the 8 grid cells holding the 8 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 989:4299 (40.525, 34.975). Over 44 years there: absolute minimum -21.0 °C, 1st-percentile night -11.7 °C, 99th-percentile day 36.5 °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 8 distinct grid cells holding the 8 in-range records; extremes and elevation at the typical cell 989:4299 (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 40.50_35.000, lapse-corrected -117 m at 6.5 °C/km. Elevation: ETOPO 2022, 865 m (cell mean).
Natural habitat
Photographs
Photographs: (c) Lucille Schmitz, some rights reserved (CC BY); no rights reserved · CC0 (3); (c) Michael Andresek, some rights reserved (CC BY); (c) George Papademetriou, some rights reserved (CC BY) (2); (c) zebedeugalinha, some rights reserved (CC BY).
Photographs: iNaturalist and Wikimedia Commons 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 Alcea rosea, 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.
Morus nigra Black Mulberry
Prunus amygdalus Almond
Knautia macedonica Macedonian scabious
Galanthus elwesii Caucasian Snowdrop
Pistacia vera Pistachio
Colchicum doerfleri ColchicaceaeHistory & 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 not askedcarried 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 127 datasets via GBIF.org; each carries its own licence.