Heracleum sphondyliumL.

Hogweedhogweedeltrot

WFO wfo-0000720220 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Heracleum sphondylium, photographed by Daniel Cahen
fig. a Daniel Cahen, CC BY 4.0 / 2022-06-12 / obs. 205532999

Every figure is a research-grade observation under CC0, CC BY or CC BY-SA, rehosted with the photographer’s name, the licence and the observation it came from. Photographs under a NonCommercial licence are excluded from this site and are never stored, which costs us a great many pictures and is not negotiable.

The specimen a real sheet, in a real collection

Herbarium
The New York Botanical Garden
Accession
02549943
Filed as
Heracleum sphondylium L.
Det. by
D. E. Atha 2016-01-01
Collected
J. V. Monachino 1937-07-09
Origin
US
The sheet
View the digitised specimen (CC BY 4.0)

A real pressed plant, in a real collection, under the accession number above. Not an illustration of one. The holding institution does not serve this sheet’s image to third parties, so there is no photograph here. The record is real and the link goes to it. Where we hold no openly licensed sheet for a species this section is simply absent, and where a sheet never recorded who determined it, that field stays empty rather than being filled in. Roughly half of all herbarium sheets never recorded a determiner, which is ordinary.

Native range 28 botanical countries

Regions where Heracleum sphondylium is native: Algeria, Morocco, Türkiye, Albania, Austria, Belgium, Bulgaria, Czechia-Slovakia, Denmark, France, Germany, Great Britain, Greece, Hungary, Ireland, Italy, Netherlands, Norway, NW. Balkan Pen., Poland, Portugal, Romania, Sicilia, Spain, Sweden, Switzerland, Türkiye-in-Europe, Ukraine AlgeriaMoroccoTürkiyeAlbaniaAustriaBelgiumBulgariaCzechia-SlovakiaDenmarkFranceGermanyGreeceHungaryIrelandItalyNetherlandsNorwayNW. Balkan Pen.PolandPortugalRomaniaSiciliaSpainSwedenSwitzerlandTürkiye-in-EuropeUkraine
Native distribution of Heracleum sphondylium, after Kew’s World Checklist of Vascular Plants. Introduced, extinct and doubtful records are excluded, so this is where the plant is from, not everywhere it now grows.
RegionTDWG codeContinent
Albania ALB EUROPE
Austria AUT
Belgium BGM
Bulgaria BUL
Czechia-Slovakia CZE
Denmark DEN
France FRA
Germany GER
Great Britain GRB
Greece GRC
Hungary HUN
Ireland IRE
Italy ITA
Netherlands NET
Norway NOR
NW. Balkan Pen. YUG
Poland POL
Portugal POR
Romania ROM
Sicilia SIC
Spain SPA
Sweden SWE
Switzerland SWI
Türkiye-in-Europe TUE
Ukraine UKR
Algeria ALG AFRICA
Morocco MOR
Türkiye TUR ASIA-TEMPERATE

Not drawn on the map: Great Britain. We hold no public-domain boundary for this region, so it is listed rather than guessed at.

Region boundaries approximated from Natural Earth (public domain) and mapped to TDWG World Geographical Scheme for Recording Plant Distributions (WGSRPD) level-3 botanical countries (Brummitt 2001). Indicative, not the official WGSRPD geometry.

Flowering 1,523 in flower of 2,627 examined

Proportion of examined Heracleum sphondylium in flower, by month
Month In flower Examined Share 95% interval
Jan 23 36 64% 48% to 78%
Feb 5 24 21% 9% to 40%
Mar 12 98 12% 7% to 20%
Apr 28 233 12% 8% to 17%
May 115 306 38% 32% to 43%
Jun 348 511 68% 64% to 72%
Jul 468 594 79% 75% to 82%
Aug 170 306 56% 50% to 61%
Sep 79 147 54% 46% to 62%
Oct 127 170 75% 68% to 81%
Nov 98 133 74% 66% to 80%
Dec 50 69 72% 61% to 82%

Peak flowering in Jul. Each bar is the share of Heracleum sphondylium observations in which someone actually recorded the reproductive state and found the plant in flower, not the raw number of flowering records. That distinction matters: people observe plants far more in spring than in winter, so a bare count of flowering records partly measures when people go outside. Dividing by the number examined removes that. 1,523 of 2,627 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. This is still a global aggregate and not a forecast for your garden: the same species flowers on different dates in different hemispheres. Where a species has fewer than 30 flowering records we do not draw this chart at all. Computed from 10.15468/dl.cgje2x.

Where it actually grows measured, from 1,948 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -8.4 °C 1.3 °C 4.2 °C
Warmest month, mean daily high 17.0 °C 20.2 °C 24.6 °C
Annual rainfall 624 mm 865 mm 1,509 mm
Rainfall in the driest quarter 111 mm 170 mm 279 mm

It is found where winters bring hard frost. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 1,948 research-grade observations of Heracleum sphondylium that carry a coordinate, and this is the range those places actually span. The 5th and 95th percentiles are used rather than the minimum and maximum, because a single cultivated specimen in a heated conservatory should not widen a tropical plant's range to the Arctic.

This is not a hardiness zone. A USDA zone is the average annual extreme minimum temperature. The figure above is the mean daily minimum of the coldest month, which is a different quantity and is typically far warmer. Reading one as the other would place a plant several zones too warm, so we do not publish a hardiness zone, because we do not have one. Climate from CHELSA V2.1 (Karger et al. 2017); occurrences from 10.15468/dl.cgje2x.

Also published as 170 synonyms

A synonym is not an error. It is a record of botanists disagreeing, in print, about where this plant belongs. Each of these was somebody’s considered answer.

  • Heracleum acuminatum Schleich.
  • Heracleum aestivum Jord.
  • Heracleum algeriense Coss. ex Batt. & Trab.
  • Heracleum alpinum L.
  • Heracleum alpinum subsp. benearnense Rouy & E.G.Camus
  • Heracleum alpinum subsp. juranum (Genty) Rouy & E.G.Camus
  • Heracleum alpinum subsp. palmatum (Baumg.) Briq.
  • Heracleum alpinum subsp. pyrenaicum (Lam.) Rouy & E.G.Camus
  • Heracleum alpinum var. pyrenaicum (Lam.) Pers.
  • Heracleum amplifolium Lapeyr.
  • Heracleum angustatum Boreau
  • Heracleum angustifolium Jacq.
  • Heracleum angustifolium M.Bieb.
  • Heracleum armoricum Boreau ex Arrond.
  • Heracleum armoricum Boreau ex Nyman
  • Heracleum artvinense Manden.
  • Heracleum asperum Mert. & W.D.J.Koch
  • Heracleum atlanticum (Coss. ex Batt.) T.Durand & B.D.Jacks.
  • Heracleum australe (Hartm.) Stankov
  • Heracleum australe Hartm.
  • Heracleum australe f. wendtioides Murb.
  • Heracleum austriacum var. elegans Crantz
  • Heracleum benearnense Rouy & E.G.Camus
  • Heracleum branca Steud.

and 146 more.

Sourcesevery claim on this page

  1. World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
  2. iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
  3. Wikidata. common name (P1843), joined on the World Flora Online identifier (P7715). CC0. Retrieved 2026-07-13.
  4. Kew, World Checklist of Vascular Plants (WCVP v16). native distribution by TDWG level-3 botanical country, and life form. CC BY 3.0. Retrieved 2026-06-04.

We publish what we can source and we say so when we cannot. This page has no care advice and no toxicity claim, because we do not yet have those from a source we can cite.