Epilobium parviflorum(Schreb.) Schreb.

Hoary Willowherbsmall-flowered willowherbsmallflower hairy willowherb

WFO wfo-0000669577 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Epilobium parviflorum, photographed by Patrick Hacker
fig. a Patrick Hacker, CC BY 4.0 / 2021-08-23 / obs. 152812155

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
Royal Botanic Gardens, Kew
Accession
K000913970
Filed as
Epilobium parviflorum Schreb.
Det. by
Hoch, P.C.
Collected
Wallich, N. 1821-01-01
Origin
NP
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 65 botanical countries

Regions where Epilobium parviflorum is native: Algeria, Azores, Canary Is., Madeira, Morocco, Tunisia, Afghanistan, China North-Central, China South-Central, China Southeast, Cyprus, East Aegean Is., Inner Mongolia, Iran, Iraq, Japan, Kazakhstan, Kirgizstan, Korea, Lebanon-Syria, North Caucasus, Palestine, Tadzhikistan, Transcaucasus, Türkiye, Turkmenistan, Uzbekistan, Xinjiang, Nepal, Pakistan, West Himalaya, Albania, Austria, Baleares, Baltic States, Belgium, Bulgaria, Central European Russia, Corse, Czechia-Slovakia, Denmark, East European Russia, Finland, France, Germany, Great Britain, Greece, Hungary, Ireland, Italy, Kriti, Netherlands, North European Russia, Northwest European Russia, Norway, NW. Balkan Pen., Poland, Portugal, Romania, Sardegna, Sicilia, Spain, Sweden, Switzerland, Türkiye-in-Europe AlgeriaMoroccoTunisiaAfghanistanChina North-CentralChina South-CentralChina SoutheastCyprusEast Aegean Is.Inner MongoliaIranIraqJapanKazakhstanKirgizstanLebanon-SyriaNorth CaucasusPalestineTadzhikistanTranscaucasusTürkiyeTurkmenistanUzbekistanXinjiangNepalPakistanWest HimalayaAlbaniaAustriaBaltic StatesBelgiumBulgariaCentral European RussiaCorseCzechia-SlovakiaDenmarkEast European RussiaFinlandFranceGermanyGreeceHungaryIrelandItalyKritiNetherlandsNorth European RussiaNorthwest European RussiaNorwayNW. Balkan Pen.PolandPortugalRomaniaSiciliaSpainSwedenSwitzerlandTürkiye-in-Europe AzoresCanary Is.MadeiraKoreaBalearesSardegna
Native distribution of Epilobium parviflorum, 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. Regions too small to draw at this scale are marked with a dot.
RegionTDWG codeContinent
Albania ALB EUROPE
Austria AUT
Baleares BAL
Baltic States BLT
Belgium BGM
Bulgaria BUL
Central European Russia RUC
Corse COR
Czechia-Slovakia CZE
Denmark DEN
East European Russia RUE
Finland FIN
France FRA
Germany GER
Great Britain GRB
Greece GRC
Hungary HUN
Ireland IRE
Italy ITA
Kriti KRI
Netherlands NET
North European Russia RUN
Northwest European Russia RUW
Norway NOR
NW. Balkan Pen. YUG
Poland POL
Portugal POR
Romania ROM
Sardegna SAR
Sicilia SIC
Spain SPA
Sweden SWE
Switzerland SWI
Türkiye-in-Europe TUE
Afghanistan AFG ASIA-TEMPERATE
China North-Central CHN
China South-Central CHC
China Southeast CHS
Cyprus CYP
East Aegean Is. EAI
Inner Mongolia CHI
Iran IRN
Iraq IRQ
Japan JAP
Kazakhstan KAZ
Kirgizstan KGZ
Korea KOR
Lebanon-Syria LBS
North Caucasus NCS
Palestine PAL
Tadzhikistan TZK
Transcaucasus TCS
Türkiye TUR
Turkmenistan TKM
Uzbekistan UZB
Xinjiang CHX
Algeria ALG AFRICA
Azores AZO
Canary Is. CNY
Madeira MDR
Morocco MOR
Tunisia TUN
Nepal NEP ASIA-TROPICAL
Pakistan PAK
West Himalaya WHM

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 124 in flower of 143 examined

Proportion of examined Epilobium parviflorum in flower, by month
Month In flower Examined Share 95% interval
Jan 0 0 too few examined
Feb 0 0 too few examined
Mar 0 0 too few examined
Apr 1 2 too few examined
May 0 0 too few examined
Jun 19 21 90% 71% to 97%
Jul 42 50 84% 71% to 92%
Aug 43 48 90% 78% to 95%
Sep 13 13 100% 77% to 100%
Oct 5 7 71% 36% to 92%
Nov 1 2 too few examined
Dec 0 0 too few examined

Peak flowering in Sep. Each bar is the share of Epilobium parviflorum 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. 124 of 143 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 7 months have fewer than 5 examined observations, so no proportion is drawn for them. 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 1,504 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -10.7 °C -3.5 °C 4.3 °C
Warmest month, mean daily high 18.4 °C 23.3 °C 27.6 °C
Annual rainfall 577 mm 860 mm 1,520 mm
Rainfall in the driest quarter 89 mm 158 mm 276 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 1,504 research-grade observations of Epilobium parviflorum 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 39 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.

  • Chamaenerion parviflorum Schreb.
  • Chamaenerion pubescens (Roth) Moench
  • Epilobium adnatum var. villosum Aidar.
  • Epilobium caballeroi Pau
  • Epilobium cordatum Biv.
  • Epilobium hirsutum var. intermedium (Mérat) Ser. ex DC.
  • Epilobium intermedium Mérat
  • Epilobium menthoides Boiss. & Heldr.
  • Epilobium molle Lam.
  • Epilobium mollissimum Schur
  • Epilobium neutrum Pall. ex Hausskn.
  • Epilobium numidicum Batt.
  • Epilobium palustre Willd.
  • Epilobium parviflorum f. apricum E.S.Marshall
  • Epilobium parviflorum f. brevifolium E.S.Marshall
  • Epilobium parviflorum f. longifolium E.S.Marshall
  • Epilobium parviflorum f. mollissimum (Welw. ex H.Lév.) Samp.
  • Epilobium parviflorum f. trifoliatum E.S.Marshall
  • Epilobium parviflorum f. umbrosum E.S.Marshall
  • Epilobium parviflorum subvar. verticillatum Coss. & Germ.
  • Epilobium parviflorum var. intermedium Rouy & E.G.Camus
  • Epilobium parviflorum var. intermedium (Mérat) St.-Lag.
  • Epilobium parviflorum var. lanuginosum Sennen
  • Epilobium parviflorum var. lusitanicum Samp.

and 15 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.