Plate 1 figs. a–g · 6 observations
This species has been photographed under an open licence only 6 times, so some figures below are different views of the same plant, taken on the same day, rather than different individuals. They are usually different parts of it: the leaf, the flower, the bark.
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.
The specimen a real sheet, in a real collection
- Herbarium
- The New York Botanical Garden
- Accession
- 1070885
- Filed as
- Hydrangea petiolaris Siebold & Zucc.
- Det. by
- D. E. Atha 2008-01-01
- Collected
- D. E. Atha 2008-06-16
- Origin
- US
- The sheet
- View the digitised specimen (CC BY 4.0)
A real pressed plant, in a real collection, under the accession number above. Not an illustration of one. The holding institution does not serve this sheet’s image to third parties, so there is no photograph here. The record is real and the link goes to it. Where we hold no openly licensed sheet for a species this section is simply absent, and where a sheet never recorded who determined it, that field stays empty rather than being filled in. Roughly half of all herbarium sheets never recorded a determiner, which is ordinary.
Native range 4 botanical countries
| Region | TDWG code | Continent |
|---|---|---|
| Japan | JAP | ASIA-TEMPERATE |
| Korea | KOR | |
| Kuril Is. | KUR | |
| Sakhalin | SAK |
Not drawn on the map: Kuril Is.. We hold no public-domain boundary for this region, so it is listed rather than guessed at.
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 241 observations
| Condition | 5th percentile | Median | 95th percentile |
|---|---|---|---|
| Coldest month, mean daily low | -13.8 °C | -7.6 °C | 1.9 °C |
| Warmest month, mean daily high | 16.0 °C | 20.6 °C | 29.7 °C |
| Annual rainfall | 748 mm | 1,245 mm | 2,675 mm |
| Rainfall in the driest quarter | 131 mm | 203 mm | 407 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 241 research-grade observations of Hydrangea petiolaris 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 15 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.
- Calyptranthe petiolaris (Siebold & Zucc.) Nakai
- Calyptranthe petiolaris var. cordifolia (Siebold & Zucc.) Nakai
- Calyptranthe petiolaris var. ovalifolia (Franch. & Sav.) Nakai
- Hydrangea anomala subsp. petiolaris (Siebold & Zucc.) E.M.McClint.
- Hydrangea anomala var. megaphylla J.M.H.Shaw
- Hydrangea anomala var. ovalifolia (Franch. & Sav.) J.M.H.Shaw
- Hydrangea bracteata Siebold & Zucc.
- Hydrangea cordifolia Siebold & Zucc.
- Hydrangea petiolaris var. bracteata (Siebold & Zucc.) Franch. & Sav.
- Hydrangea petiolaris var. cordifolia (Siebold & Zucc.) Franch. & Sav.
- Hydrangea petiolaris var. ovalifolia Franch. & Sav.
- Hydrangea scandens Maxim.
- Hydrangea scandens var. cordifolia (Siebold & Zucc.) Maxim.
- Hydrangea scandens var. petiolaris (Siebold & Zucc.) Maxim.
- Hydrangea tilaefolia H.Lév.
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.
- 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.