Penstemon spectabilis (showy penstemon)

Plate 1 figs. a–h · 8 separate observations

Penstemon spectabilis, photographed by Millie Basden — fig. a Millie Basden, CC BY 4.0 / 2022-05-29 / obs. 201704518

Penstemon spectabilis, photographed by Marc Whitaker — fig. b Marc Whitaker, CC BY 4.0 / obs. 200359844

Penstemon spectabilis, photographed by velodrome — fig. c velodrome, CC BY 4.0 / obs. 201768650

Penstemon spectabilis, photographed by James C. Davis — fig. g James C. Davis, CC BY-SA 4.0 / obs. 192692600

Penstemon spectabilis, photographed by Trevor Van Loon — fig. h Trevor Van Loon, CC BY 4.0 / obs. 186327459

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 2 botanical countries

Native distribution of Penstemon spectabilis, 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
California	CAL	NORTHERN AMERICA
Mexico Northwest	MXN

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 451 in flower of 554 examined

50%

33%

74%

81%

93%

65%

36%

50%

22%

Proportion of examined Penstemon spectabilis in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	7	14	50%	27% to 73%
Feb	2	6	33%	10% to 70%
Mar	20	27	74%	55% to 87%
Apr	87	107	81%	73% to 88%
May	208	223	93%	89% to 96%
Jun	99	106	93%	87% to 97%
Jul	15	23	65%	45% to 81%
Aug	0	5	0%	0% to 43%
Sep	0	9	0%	0% to 30%
Oct	4	11	36%	15% to 65%
Nov	7	14	50%	27% to 73%
Dec	2	9	22%	6% to 55%

Peak flowering in Jun. Each bar is the share of Penstemon spectabilis 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. 451 of 554 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.

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.

Penstemon spectabilis subsp. spectabilis
Penstemon spectabilis subsp. subinteger D.D.Keck
Penstemon spectabilis subsp. subviscosus D.D.Keck
Penstemon spectabilis subsp. typicus D.D.Keck
Penstemon spectabilis var. gilmanii Jeps.

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.