Epilobium billardiereanumSer.

aboriginal willowherb

WFO wfo-0000668816 Accepted WFO 2026-06 8 photographs CC BY / CC BY-SA

Plate 1 figs. a–h · 8 separate observations

Epilobium billardiereanum, photographed by Arnim Littek
fig. a Arnim Littek, CC BY 4.0 / 2022-03-11 / obs. 182512334

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
Smithsonian, US National Herbarium
Accession
US 2277347
Filed as
Epilobium billardiereanum subsp. cinereum (A.Rich.) P.H.Raven & Engelhorn
Det. by
Wagner, W. L., (BOT), Smithsonian Institution - National Museum of Natural History (UNITED STATES)
Collected
F. R. Fosberg 1933-08-23
Origin
US
The sheet
View the digitised specimen (CC0 1.0)

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 10 botanical countries

Regions where Epilobium billardiereanum is native: Chatham Is., New South Wales, New Zealand North, New Zealand South, Norfolk Is., Queensland, South Australia, Tasmania, Victoria, Western Australia New South WalesNew Zealand NorthNew Zealand SouthQueenslandSouth AustraliaTasmaniaVictoriaWestern Australia Chatham Is.Norfolk Is.
Native distribution of Epilobium billardiereanum, 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
Chatham Is. CTM AUSTRALASIA
New South Wales NSW
New Zealand North NZN
New Zealand South NZS
Norfolk Is. NFK
Queensland QLD
South Australia SOA
Tasmania TAS
Victoria VIC
Western Australia WAU

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 62 in flower of 237 examined

Proportion of examined Epilobium billardiereanum in flower, by month
Month In flower Examined Share 95% interval
Jan 21 48 44% 31% to 58%
Feb 8 21 38% 21% to 59%
Mar 2 17 12% 3% to 34%
Apr 2 18 11% 3% to 33%
May 1 10 10% 2% to 40%
Jun 0 12 0% 0% to 24%
Jul 0 10 0% 0% to 28%
Aug 0 10 0% 0% to 28%
Sep 0 7 0% 0% to 35%
Oct 3 17 18% 6% to 41%
Nov 5 27 19% 8% to 37%
Dec 20 40 50% 35% to 65%

Peak flowering in Dec. Each bar is the share of Epilobium billardiereanum 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. 62 of 237 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 463 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low 1.6 °C 7.3 °C 9.4 °C
Warmest month, mean daily high 19.2 °C 20.8 °C 25.4 °C
Annual rainfall 646 mm 1,092 mm 1,495 mm
Rainfall in the driest quarter 124 mm 216 mm 286 mm

It is found where winters are cool but frost is light or absent. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 463 research-grade observations of Epilobium billardiereanum 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 28 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.

  • Epilobium baueri Endl.
  • Epilobium billardiereanum var. simplex (Hausskn.) Kirk
  • Epilobium billardierianum f. major Hausskn.
  • Epilobium billardierianum f. simplex Hausskn.
  • Epilobium billardierianum var. simplex (Hausskn.) Kirk
  • Epilobium canescens Endl.
  • Epilobium canescens var. glabrescens Nees
  • Epilobium cinereum A.Rich.
  • Epilobium confertum A.Cunn.
  • Epilobium glabellum R.Br. ex Hausskn.
  • Epilobium glabellum var. billardierianum (DC.) Maiden & Betche
  • Epilobium incanum A.Cunn.
  • Epilobium junceum f. canescens Hausskn.
  • Epilobium junceum f. cinereum Hausskn.
  • Epilobium junceum f. macrophylla Hausskn.
  • Epilobium junceum f. minor Hausskn.
  • Epilobium junceum f. teucriifolium Hausskn.
  • Epilobium junceum subf. microphyllum Hausskn.
  • Epilobium junceum subsp. serratifolium Hausskn.
  • Epilobium junceum var. caninum H.Lév.
  • Epilobium junceum var. cinereum (A.Rich.) Kirk
  • Epilobium junceum var. corymbosum H.Lév.
  • Epilobium junceum var. macrophyllum (Hausskn.) Cheeseman
  • Epilobium junceum var. macrophyllum Hausskn.

and 4 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.