Plagiorhegma dubiumMaxim.

WFO wfo-0001146550 Accepted WFO 2026-06 8 photographs CC BY

Plate 1 figs. a–h · 8 separate observations

Plagiorhegma dubium, photographed by Nina Filippova
fig. a Nina Filippova, CC BY 4.0 / 2021-08-29 / obs. 153911569
Plagiorhegma dubium, photographed by Nina Filippova
fig. b Nina Filippova, CC BY 4.0 / obs. 153672326
Plagiorhegma dubium, photographed by Nina Filippova
fig. c Nina Filippova, CC BY 4.0 / obs. 153673388
Plagiorhegma dubium, photographed by Nina Filippova
fig. d Nina Filippova, CC BY 4.0 / obs. 153461844
Plagiorhegma dubium, photographed by Nina Filippova
fig. e Nina Filippova, CC BY 4.0 / obs. 153313269
Plagiorhegma dubium, photographed by Nina Filippova
fig. f Nina Filippova, CC BY 4.0 / obs. 152912042
Plagiorhegma dubium, photographed by Repina Tatyana
fig. g Repina Tatyana, CC BY 4.0 / obs. 123966636
Plagiorhegma dubium, photographed by Николай Соболев
fig. h Николай Соболев, CC BY 4.0 / obs. 115914620

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 4 botanical countries

Regions where Plagiorhegma dubium is native: Khabarovsk, Korea, Manchuria, Primorye KhabarovskManchuriaPrimorye Korea
Native distribution of Plagiorhegma dubium, 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. Regions too small to draw at this scale are marked with a dot.
RegionTDWG codeContinent
Khabarovsk KHA ASIA-TEMPERATE
Korea KOR
Manchuria CHM
Primorye PRM

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 198 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -23.8 °C -17.0 °C -12.5 °C
Warmest month, mean daily high 21.2 °C 23.4 °C 25.7 °C
Annual rainfall 573 mm 788 mm 942 mm
Rainfall in the driest quarter 33 mm 46 mm 75 mm

It is found where winters are severely cold. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 198 research-grade observations of Plagiorhegma dubium 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 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.

  • Jeffersonia dubia (Maxim.) Benth. & Hook.f. ex Baker & Moore
  • Jeffersonia manchuriensis Hance

Sourcesevery claim on this page

  1. World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
  2. iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
  3. 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.