Physaria acutifolia (sharpleaf twinpod)

Plate 1 figs. a–h · 8 separate observations

Physaria acutifolia, photographed by Reid Hardin — fig. a Reid Hardin, CC BY 4.0 / 2021-07-15 / obs. 144467322

Physaria acutifolia, photographed by Mitch Van Dyke — fig. c Mitch Van Dyke, CC BY 4.0 / obs. 80338594

Physaria acutifolia, photographed by Cecelia Alexander — fig. d Cecelia Alexander, CC0 1.0 / obs. 18714556

Physaria acutifolia, photographed by Jess Mullins — fig. e Jess Mullins, CC BY 4.0 / obs. 17197744

Physaria acutifolia, photographed by Robbie Hannawacker — fig. f Robbie Hannawacker, CC0 1.0 / obs. 7806219

Physaria acutifolia, photographed by Todd Boland — fig. h Todd Boland, CC BY 4.0 / obs. 12622178

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 9 botanical countries

Native distribution of Physaria acutifolia, 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.

Region	TDWG code	Continent
Arizona	ARI	NORTHERN AMERICA
Colorado	COL
Idaho	IDA
Montana	MNT
Nevada	NEV
New Mexico	NWM
South Dakota	SDA
Utah	UTA
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 44 in flower of 111 examined

60%

64%

34%

13%

33%

Proportion of examined Physaria acutifolia in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	0	1	too few examined
Feb	2	2	too few examined
Mar	6	10	60%	31% to 83%
Apr	16	25	64%	45% to 80%
May	16	47	34%	22% to 48%
Jun	2	15	13%	4% to 38%
Jul	2	6	33%	10% to 70%
Aug	0	3	too few examined
Sep	0	2	too few examined
Oct	0	0	too few examined
Nov	0	0	too few examined
Dec	0	0	too few examined

Peak flowering in Apr. Each bar is the share of Physaria acutifolia 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. 44 of 111 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 328 observations

Condition	5th percentile	Median	95th percentile
Coldest month, mean daily low	-12.7 °C	-9.3 °C	-5.7 °C
Warmest month, mean daily high	25.3 °C	30.4 °C	33.7 °C
Annual rainfall	229 mm	346 mm	489 mm
Rainfall in the driest quarter	37 mm	58 mm	81 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 328 research-grade observations of Physaria acutifolia 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 5 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.

Physaria acutifolia var. acutifolia Rydb.
Physaria acutifolia var. stylosa (Rollins) S.L.Welsh
Physaria australis (Payson) Rollins
Physaria didymocarpa var. australis Payson
Physaria stylosa Rollins

Sourcesevery claim on this page

World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
Wikidata. common name (P1843), joined on the World Flora Online identifier (P7715). CC0. Retrieved 2026-07-13.
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.