Physostegia parviflora (western false dragonhead)

Plate 1 figs. a–h · 4 observations

This species has been photographed under an open licence only 4 times, so some figures below are different views of the same plant, taken on the same day, rather than different individuals. They are usually different parts of it: the leaf, the flower, the bark.

Physostegia parviflora, photographed by Nolan Exe — fig. a Nolan Exe, CC BY 4.0 / 2020-07-09 / obs. 88564150

Physostegia parviflora, photographed by Kate — fig. e Kate, CC BY 4.0 / obs. 148823819

Physostegia parviflora, photographed by tonyblake — fig. h tonyblake, CC0 1.0 / obs. 4608212

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 12 botanical countries

Native distribution of Physostegia parviflora, 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
British Columbia	BRC	NORTHERN AMERICA
Idaho	IDA
Illinois	ILL
Manitoba	MAN
Montana	MNT
Nebraska	NEB
North Dakota	NDA
Oregon	ORE
Saskatchewan	SAS
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.

Where it actually grows measured, from 75 observations

Condition	5th percentile	Median	95th percentile
Coldest month, mean daily low	-10.6 °C	-7.5 °C	-4.3 °C
Warmest month, mean daily high	24.5 °C	27.5 °C	29.0 °C
Annual rainfall	277 mm	488 mm	1,072 mm
Rainfall in the driest quarter	41 mm	87 mm	203 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 75 research-grade observations of Physostegia parviflora 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.

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.

Dracocephalum nuttallii Britton
Moldavica parviflora (Nutt. ex A.Gray) Britton
Physostegia imbricata Benth.
Physostegia nuttallii (Britton) Fassett
Physostegia virginiana var. parviflora (Nutt. ex A.Gray) B.Boivin

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.