Plate 1 figs. a–h · 8 separate observations
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 22 botanical countries
| Region | TDWG code | Continent |
|---|---|---|
| Alaska | ASK | NORTHERN AMERICA |
| Alberta | ABT | |
| Arizona | ARI | |
| British Columbia | BRC | |
| California | CAL | |
| Colorado | COL | |
| Idaho | IDA | |
| Manitoba | MAN | |
| Montana | MNT | |
| Nebraska | NEB | |
| Nevada | NEV | |
| New Mexico | NWM | |
| North Dakota | NDA | |
| Northwest Territories | NWT | |
| Ontario | ONT | |
| Oregon | ORE | |
| Saskatchewan | SAS | |
| South Dakota | SDA | |
| Utah | UTA | |
| Washington | WAS | |
| Wyoming | WYO | |
| Yukon | YUK |
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 1,980 observations
| Condition | 5th percentile | Median | 95th percentile |
|---|---|---|---|
| Coldest month, mean daily low | -14.9 °C | -10.1 °C | -4.3 °C |
| Warmest month, mean daily high | 21.5 °C | 25.0 °C | 31.1 °C |
| Annual rainfall | 257 mm | 434 mm | 804 mm |
| Rainfall in the driest quarter | 32 mm | 54 mm | 109 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 1,980 research-grade observations of Betula occidentalis 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 Reading one as the other would place a plant several zones too warm, so we do not publish a hardiness zone, because we do not have one.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 16 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.
- Betula alba f. occidentalis (Hook.) Fernald
- Betula alba subsp. occidentalis (Hook.) Regel
- Betula beeniana A.Nelson
- Betula elrodiana E.J.Butler
- Betula fontinalis Sarg.
- Betula fontinalis f. inopina Jeps.
- Betula fontinalis var. inopina (Jeps.) Jeps.
- Betula microphylla var. fontinalis (Sarg.) M.E.Jones
- Betula microphylla var. occidentalis (Hook.) M.E.Jones
- Betula occidentalis f. inopina Jeps.
- Betula occidentalis subsp. inopina (Jeps.) A.E.Murray
- Betula occidentalis var. inopina (Jeps.) C.L.Hitchc.
- Betula occidentalis var. occidentalis
- Betula papyracea var. occidentalis (Hook.) Dippel
- Betula papyrifera subsp. occidentalis (Hook.) Hultén
- Betula papyrifera var. occidentalis (Hook.) Sarg.
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.