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 28 botanical countries
| Region | TDWG code | Continent |
|---|---|---|
| Assam | ASS | ASIA-TROPICAL |
| Bangladesh | BAN | |
| Cambodia | CBD | |
| East Himalaya | EHM | |
| India | IND | |
| Jawa | JAW | |
| Lesser Sunda Is. | LSI | |
| Malaya | MLY | |
| Myanmar | MYA | |
| New Guinea | NWG | |
| Philippines | PHI | |
| Sri Lanka | SRL | |
| Thailand | THA | |
| Vietnam | VIE | |
| West Himalaya | WHM | |
| Amur | AMU | ASIA-TEMPERATE |
| China North-Central | CHN | |
| China South-Central | CHC | |
| China Southeast | CHS | |
| Hainan | CHH | |
| Khabarovsk | KHA | |
| Korea | KOR | |
| Manchuria | CHM | |
| Primorye | PRM | |
| Taiwan | TAI | |
| New South Wales | NSW | AUSTRALASIA |
| Northern Territory | NTA | |
| Queensland | QLD |
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 95 in flower of 101 examined
Peak flowering in Jan. Each bar is the share of Persicaria orientalis 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. 95 of 101 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. 4 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 562 observations
| Condition | 5th percentile | Median | 95th percentile |
|---|---|---|---|
| Coldest month, mean daily low | -16.8 °C | -3.3 °C | 14.3 °C |
| Warmest month, mean daily high | 22.3 °C | 28.3 °C | 31.6 °C |
| Annual rainfall | 504 mm | 900 mm | 3,771 mm |
| Rainfall in the driest quarter | 11 mm | 119 mm | 626 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 562 research-grade observations of Persicaria orientalis 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 21 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.
- Amblygonum orientale (L.) Nakai
- Amblygonum orientale var. pilosum (Roxb. ex Meisn.) Nakai
- Amblygonum orientale var. pilosum (Roxb. ex Meisn.) Nakai ex T.Mori
- Amblygonum pilosum (Meisn.) Nakai
- Goniaticum solitarium Stokes
- Heptarina orientalis (L.) Raf.
- Lagunea cochinchinensis Lour.
- Lagunea orientalis (L.) Nakai
- Lagunea orientalis var. pilosa (Roxb. ex Meisn.) Nakai
- Persicaria cochinchinensis (Lour.) Kitag.
- Persicaria pilosa (Roxb.) Kitag.
- Polygonum amoenum Blume
- Polygonum cochinchinense (Lour.) Meisn.
- Polygonum cordobense Lindau
- Polygonum orientale L.
- Polygonum orientale var. discolor Benth.
- Polygonum orientale var. pilosum (Roxb. ex Meisn.) Meisn.
- Polygonum pilosum Wall.
- Polygonum pilosum Roxb.
- Polygonum torquatum De Bruyn
- Polygonum torquatum De Bruyn
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 POOR2. 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.