Trifolium productum (Shasta clover)

Plate 1 figs. a–h · 8 separate observations

Trifolium productum, photographed by John Brew — fig. a John Brew, CC BY 4.0 / 2021-06-28 / obs. 143312823

Trifolium productum, photographed by Drew Meyer — fig. b Drew Meyer, CC0 1.0 / obs. 130173291

Trifolium productum, photographed by Alan Weakley — fig. c Alan Weakley, CC0 1.0 / obs. 50330041

Trifolium productum, photographed by Scott Loarie — fig. d Scott Loarie, CC0 1.0 / obs. 385065

Trifolium productum, photographed by Craig Martin — fig. e Craig Martin, CC0 1.0 / obs. 105087506

Trifolium productum, photographed by Don Loarie — fig. f Don Loarie, CC BY 4.0 / obs. 84870978

Trifolium productum, photographed by Monika Fischer — fig. h Monika Fischer, CC0 1.0 / obs. 84735240

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 3 botanical countries

Native distribution of Trifolium productum, 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
Nevada	NEV
Oregon	ORE

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 378 in flower of 398 examined

89%

100%

96%

86%

100%

Proportion of examined Trifolium productum in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	0	0	too few examined
Feb	0	0	too few examined
Mar	0	0	too few examined
Apr	1	1	too few examined
May	8	9	89%	56% to 98%
Jun	104	104	100%	96% to 100%
Jul	200	209	96%	92% to 98%
Aug	60	70	86%	76% to 92%
Sep	5	5	100%	57% to 100%
Oct	0	0	too few examined
Nov	0	0	too few examined
Dec	0	0	too few examined

Peak flowering in Jun. Each bar is the share of Trifolium productum 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. 378 of 398 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.

Also published as 2 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.

Trifolium kingii subsp. productum (Greene) D.Heller
Trifolium kingii var. productum (Greene) 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.
USDA PLANTS Database. common name, checklist symbol TRPR4. public domain. 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.