Chaenactis douglasiiHook. & Arn.

Douglas' dustymaiden

WFO wfo-0000043449 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Chaenactis douglasii, photographed by James H. Thomas
fig. a James H. Thomas, CC BY 4.0 / 2022-05-29 / obs. 202037318

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.

Native range 15 botanical countries

Regions where Chaenactis douglasii is native: Alberta, Arizona, British Columbia, California, Colorado, Idaho, Montana, Nevada, New Mexico, North Dakota, Oregon, South Dakota, Utah, Washington, Wyoming AlbertaArizonaBritish ColumbiaCaliforniaColoradoIdahoMontanaNevadaNew MexicoNorth DakotaOregonSouth DakotaUtahWashingtonWyoming
Native distribution of Chaenactis douglasii, 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
Alberta ABT NORTHERN AMERICA
Arizona ARI
British Columbia BRC
California CAL
Colorado COL
Idaho IDA
Montana MNT
Nevada NEV
New Mexico NWM
North Dakota NDA
Oregon ORE
South Dakota SDA
Utah UTA
Washington WAS
Wyoming WYO

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 319 in flower of 539 examined

Proportion of examined Chaenactis douglasii in flower, by month
Month In flower Examined Share 95% interval
Jan 0 5 0% 0% to 43%
Feb 0 6 0% 0% to 39%
Mar 0 21 0% 0% to 15%
Apr 3 21 14% 5% to 35%
May 54 143 38% 30% to 46%
Jun 135 151 89% 83% to 93%
Jul 96 118 81% 73% to 87%
Aug 24 34 71% 54% to 83%
Sep 6 17 35% 17% to 59%
Oct 1 7 14% 3% to 51%
Nov 0 10 0% 0% to 28%
Dec 0 6 0% 0% to 39%

Peak flowering in Jun. Each bar is the share of Chaenactis douglasii 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. 319 of 539 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 2,016 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -17.2 °C -7.8 °C -3.0 °C
Warmest month, mean daily high 19.3 °C 27.5 °C 32.3 °C
Annual rainfall 208 mm 411 mm 1,493 mm
Rainfall in the driest quarter 20 mm 53 mm 166 mm

It is found where winters are severely cold. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 2,016 research-grade observations of Chaenactis douglasii 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 34 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.

  • Chaenactis achilleifolia Hook. & Arn.
  • Chaenactis achilleifolia var. achilleifolia
  • Chaenactis achilleifolia var. douglasii (Hook. & Arn.) A.Gray
  • Chaenactis alpina M.E.Jones
  • Chaenactis alpina subsp. alpina
  • Chaenactis alpina var. alpina
  • Chaenactis alpina var. rubella (Greene) Stockw.
  • Chaenactis angustifolia Greene
  • Chaenactis brachiata Greene
  • Chaenactis brachiata var. brachiata
  • Chaenactis brachiata var. stansburyana Stockw.
  • Chaenactis cheilanthoides Greene
  • Chaenactis cinerea Stockw.
  • Chaenactis douglasii var. achilleifolia (Hook. & Arn.) A.Gray
  • Chaenactis douglasii var. achilleifolia (Hook. & Arn.) A.Nelson
  • Chaenactis douglasii var. glandulosa Cronquist
  • Chaenactis douglasii var. montana M.E.Jones
  • Chaenactis douglasii var. nana Stockw.
  • Chaenactis douglasii var. ramosa Stockw.
  • Chaenactis douglasii var. ramosior Cronquist
  • Chaenactis humilis Rydb.
  • Chaenactis imbricata Greene
  • Chaenactis leucopsis Greene
  • Chaenactis minuscula Greene

and 10 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.