Humulus scandens (Japanese hop)

Plate 1 figs. a–h · 8 separate observations

Humulus scandens, photographed by Robert Hoard — fig. a Robert Hoard, CC0 1.0 / 2022-06-05 / obs. 203573272

Humulus scandens, photographed by Zinogre — fig. b Zinogre, CC BY-SA 4.0 / obs. 203448779

Humulus scandens, photographed by 潘立傑 LICHIEH_PAN — fig. f 潘立傑 LICHIEH_PAN, CC BY 4.0 / obs. 189964486

Humulus scandens, photographed by 葉子 — fig. h 葉子, CC0 1.0 / obs. 196992728

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 14 botanical countries

Native distribution of Humulus scandens, 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.

Region	TDWG code	Continent
China North-Central	CHN	ASIA-TEMPERATE
China South-Central	CHC
China Southeast	CHS
Hainan	CHH
Inner Mongolia	CHI
Japan	JAP
Khabarovsk	KHA
Korea	KOR
Manchuria	CHM
Nansei-shoto	NNS
Primorye	PRM
Taiwan	TAI
Tibet	CHT
Vietnam	VIE	ASIA-TROPICAL

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 165 in flower of 534 examined

40%

43%

21%

24%

10%

48%

43%

39%

27%

40%

Proportion of examined Humulus scandens in flower, by month
Month	In flower	Examined	Share	95% interval
Jan	2	5	40%	12% to 77%
Feb	3	7	43%	16% to 75%
Mar	4	19	21%	9% to 43%
Apr	9	38	24%	13% to 39%
May	6	60	10%	5% to 20%
Jun	4	43	9%	4% to 22%
Jul	3	52	6%	2% to 16%
Aug	62	130	48%	39% to 56%
Sep	45	104	43%	34% to 53%
Oct	19	49	39%	26% to 53%
Nov	6	22	27%	13% to 48%
Dec	2	5	40%	12% to 77%

Peak flowering in Aug. Each bar is the share of Humulus scandens 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. 165 of 534 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 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 7 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.

Antidesma scandens Lour.
Humulopsis scandens (Lour.) Grudz.
Humulus aculeatus Nutt.
Humulus japonicus Siebold & Zucc.
Humulus japonicus var. minor Nakai
Humulus japonicus var. variegatus F.Roem.
Humulus scandens var. variegatus (Siebold & Zucc.) Moldenke

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 HUJA. 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.