Phacelia tanacetifoliaBenth.

lacy phaceliaphacelia

WFO wfo-0000465176 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Phacelia tanacetifolia, photographed by Stephan Mende
fig. a Stephan Mende, CC BY 4.0 / 2022-06-09 / obs. 205127168

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
02313197
Filed as
Phacelia tanacetifolia var. latifolia Torr.
Det. by
D. Atwood
Collected
N. H. Holmgren 1973-03-26
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 4 botanical countries

Regions where Phacelia tanacetifolia is native: Arizona, California, Mexico Northwest, Nevada ArizonaCaliforniaMexico NorthwestNevada
Native distribution of Phacelia tanacetifolia, 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
Arizona ARI NORTHERN AMERICA
California CAL
Mexico Northwest MXN
Nevada NEV

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 960 in flower of 1,024 examined

Proportion of examined Phacelia tanacetifolia in flower, by month
Month In flower Examined Share 95% interval
Jan 14 18 78% 55% to 91%
Feb 27 31 87% 71% to 95%
Mar 74 82 90% 82% to 95%
Apr 119 132 90% 84% to 94%
May 238 246 97% 94% to 98%
Jun 202 204 99% 97% to 100%
Jul 84 87 97% 90% to 99%
Aug 54 62 87% 77% to 93%
Sep 43 47 91% 80% to 97%
Oct 58 64 91% 81% to 96%
Nov 38 39 97% 87% to 100%
Dec 9 12 75% 47% to 91%

Peak flowering in Jun. Each bar is the share of Phacelia tanacetifolia 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. 960 of 1,024 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.

When it blooms, where you are 1 state

StatePeaksObservations in flower
California Feb 191

Where it actually grows measured, from 1,992 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -10.9 °C 0.3 °C 5.0 °C
Warmest month, mean daily high 18.5 °C 22.8 °C 34.6 °C
Annual rainfall 245 mm 714 mm 1,207 mm
Rainfall in the driest quarter 4 mm 129 mm 222 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 1,992 research-grade observations of Phacelia tanacetifolia 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 3 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.

  • Phacelia commixta Greene
  • Phacelia tanacetifolia var. pseudodistans (Benth.) Brand
  • Phacelia tripinnata Fisch., C.A.Mey. & Avé-Lall.

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.