Kerria japonica(L.) DC.

Japanese roseYellow rose

WFO wfo-0001008321 Accepted WFO 2026-06 8 photographs CC0 / CC BY / CC BY-SA

Plate 1 figs. a–h · 8 separate observations

Kerria japonica, photographed by Susan Berry
fig. a Susan Berry, CC0 1.0 / 2022-05-19 / obs. 202334392

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 5 botanical countries

Regions where Kerria japonica is native: China North-Central, China South-Central, China Southeast, Japan, Korea China North-CentralChina South-CentralChina SoutheastJapan Korea
Native distribution of Kerria japonica, 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
China North-Central CHN ASIA-TEMPERATE
China South-Central CHC
China Southeast CHS
Japan JAP
Korea KOR

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 293 in flower of 300 examined

Proportion of examined Kerria japonica in flower, by month
Month In flower Examined Share 95% interval
Jan 1 1 too few examined
Feb 1 1 too few examined
Mar 31 31 100% 89% to 100%
Apr 138 139 99% 96% to 100%
May 68 68 100% 95% to 100%
Jun 13 14 93% 69% to 99%
Jul 8 10 80% 49% to 94%
Aug 11 12 92% 65% to 99%
Sep 8 8 100% 68% to 100%
Oct 3 4 too few examined
Nov 5 5 100% 57% to 100%
Dec 6 7 86% 49% to 97%

Peak flowering in Mar. Each bar is the share of Kerria japonica 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. 293 of 300 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 3 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.

Where it actually grows measured, from 2,006 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -8.8 °C -1.4 °C 3.1 °C
Warmest month, mean daily high 19.3 °C 26.1 °C 31.2 °C
Annual rainfall 596 mm 1,184 mm 2,164 mm
Rainfall in the driest quarter 74 mm 169 mm 303 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 2,006 research-grade observations of Kerria japonica 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. Climate from CHELSA V2.1 (Karger et al. 2017); occurrences from 10.15468/dl.cgje2x.

Also published as 31 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.

  • Corchorus japonicus Thunb.
  • Kerria japonica f. albescens (Makino) Ohwi
  • Kerria japonica f. aureovariegata (Rehder) Rehder
  • Kerria japonica f. aureovittata (Hartwig & Rümpler) Rehder
  • Kerria japonica f. picta (Siebold) Rehder
  • Kerria japonica f. plena C.K.Schneid.
  • Kerria japonica f. pleniflora (Witte) Rehder
  • Kerria japonica f. semiplena Hayashi
  • Kerria japonica f. stellata (Makino) Ohwi
  • Kerria japonica f. typica Nakai
  • Kerria japonica f. vittatoramosa Zabel
  • Kerria japonica unranked argenteomarginatis Jacob-Makoy
  • Kerria japonica unranked aureovariegata Bean
  • Kerria japonica unranked variegata T.Moore
  • Kerria japonica var. albescens Makino ex Koidz.
  • Kerria japonica var. argenteovariegata Lem.
  • Kerria japonica var. aureovariegata Rehder
  • Kerria japonica var. aureovittata Hartwig & Rümpler
  • Kerria japonica var. denticulata L.C.Wang & X.G.Sun
  • Kerria japonica var. flore-pleno Wyman
  • Kerria japonica var. floribus-plenis Siebold & Zucc.
  • Kerria japonica var. floribus-simplicibus Siebold & Zucc.
  • Kerria japonica var. foliis-variegatis Siebold & Zucc.
  • Kerria japonica var. grandiflora Wyman

and 7 more.

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. Wikidata. common name (P1843), joined on the World Flora Online identifier (P7715). CC0. Retrieved 2026-07-13.
  4. 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.