Polygonum douglasii
Greene
Polygonaceae
Polygonum buxiforme montanum (Brenckle) R.J.Davis
Polygonum commixtum Greene
Polygonum howellii Greene
Polygonum montanum (Small) Greene
Polygonum tenue commune Engelm.
Polygonum tenue latifolium Engelm.
Polygonum vagans Greene
Common Name: Douglas' Knotweed
General Information
Polygonum douglasii is an erect, unbranched or branched, annual plant that can grow around 5 - 80cm tall[
270- Title
- Flora of N. America
- Publication
-
- Author
-
- Website
- http://flora.huh.harvard.edu/fna/
- Publisher
-
- Year
- 0
- ISBN
-
- Description
- An on-line version of the flora with an excellent description of the plant including a brief mention of plant uses.
].
The plant is harvested from the wild for local use as a food.
Known Hazards
Although no specific mention has been made for this species, there have been reports that some members of this genus can cause photosensitivity in susceptible people.
Many species also contain oxalic acid (the distinctive lemony flavour of sorrel) - whilst not toxic this substance can bind up other minerals making them unavailable to the body and leading to mineral deficiency. Having said that, a number of common foods such as sorrel and rhubarb contain oxalic acid and the leaves of most members of this genus are nutritious and beneficial to eat in moderate quantities. Cooking the leaves will reduce their content of oxalic acid. People with a tendency to rheumatism, arthritis, gout, kidney stones or hyperacidity should take especial caution if including this plant in their diet since it can aggravate their condition[
238- Title
- Encyclopaedia of Herbs and their Uses.
- Publication
-
- Author
- Bown. D.
- Publisher
- Dorling Kindersley, London.
- Year
- 1995
- ISBN
- 0-7513-020-31
- Description
- A very well presented and informative book on herbs from around the globe. Plenty in it for both the casual reader and the serious student. Just one main quibble is the silly way of having two separate entries for each plant.
].
Botanical References
43- Title
- Gray's Manual of Botany.Eighth Edition
- Publication
-
- Author
- Fernald. M. L.
- Publisher
- American Book Co.; New York
- Year
- 1950
- ISBN
- 0442222505
- Description
- A bit dated but a good and concise flora of the eastern part of N. America.
,
60- Title
- Vascular Plants of the Pacific Northwest.
- Publication
-
- Author
- Hitchcock. C. L.
- Publisher
- University of Washington Press
- Year
- 1955
- ISBN
- -
- Description
- A standard flora for Western N. America with lots of information on habitat etc. Five large volumes, it is not for the casual reader.
,
270- Title
- Flora of N. America
- Publication
-
- Author
-
- Website
- http://flora.huh.harvard.edu/fna/
- Publisher
-
- Year
- 0
- ISBN
-
- Description
- An on-line version of the flora with an excellent description of the plant including a brief mention of plant uses.
Range
N. America - Yukon and British Columbia to Quebec, south to California and NW Mexico, New Mexico, Iowa, Michigan and New Hampshire
Habitat
Dry, often disturbed places, rock outcrops, sandy ground; at elevations from 300 - 3,000 metres[
270- Title
- Flora of N. America
- Publication
-
- Author
-
- Website
- http://flora.huh.harvard.edu/fna/
- Publisher
-
- Year
- 0
- ISBN
-
- Description
- An on-line version of the flora with an excellent description of the plant including a brief mention of plant uses.
].
Properties
| Edibility Rating |  |
| Habit | Annual |
| Height | 0.30 m |
| Pollinators | Insects |
| Cultivation Status | Wild |
Cultivation Details
Species in this genus generally succeed in an ordinary garden soil, whilst preferring a moisture retentive not too fertile soil in sun or part shade[
200- Title
- The New RHS Dictionary of Gardening. 1992.
- Publication
-
- Author
- Huxley. A.
- Publisher
- MacMillan Press
- Year
- 1992
- ISBN
- 0-333-47494-5
- Description
- Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
]. They generally rpays generous treatment[
1- Title
- RHS Dictionary of Plants plus Supplement. 1956
- Publication
-
- Author
- F. Chittendon.
- Publisher
- Oxford University Press
- Year
- 1951
- ISBN
- -
- Description
- Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaced in 1992 by a new dictionary (see [200]).
].
Most plants in this genus seem to be immune to the predations of rabbits[
233- Title
- Perennial Garden Plants
- Publication
-
- Author
- Thomas. G. S.
- Publisher
- J. M. Dent & Sons, London.
- Year
- 1990
- ISBN
- 0 460 86048 8
- Description
- A concise guide to a wide range of perennials. Lots of cultivation guides, very little on plant uses.
].
Edible Uses
Leaves - raw or cooked.
Seed - dried then ground into a powder and mixed with cornmeal or other cereals for making bread etc[
46- Title
- Dictionary of Economic Plants.
- Publication
-
- Author
- Uphof. J. C. Th.
- Publisher
- Weinheim
- Year
- 1959
- ISBN
- -
- Description
- An excellent and very comprehensive guide but it only gives very short descriptions of the uses without any details of how to utilize the plants. Not for the casual reader.
,
61- Title
- A Dictionary of Plants Used by Man.
- Publication
-
- Author
- Usher. G.
- Publisher
- Constable
- Year
- 1974
- ISBN
- 0094579202
- Description
- Forget the sexist title, this is one of the best books on the subject. Lists a very extensive range of useful plants from around the world with very brief details of the uses. Not for the casual reader.
,
105- Title
- Tanaka's Cyclopedia of Edible Plants of the World.
- Publication
-
- Author
- Tanaka. T. & Nakao S.
- Publisher
- Keigaku Publishing; Tokyo
- Year
- 1976
- ISBN
- -
- Description
- The most comprehensive list of edible plants I've come across. Only the briefest entry for each species, though, and some of the entries are more than a little dubious. Not for the casual reader.
,
161- Title
- Food Plants of the N. American Indians. Publication no. 237.
- Publication
-
- Author
- Yanovsky. E.
- Publisher
- U.S. Depf of Agriculture.
- Year
-
- ISBN
- -
- Description
- A comprehensive but very terse guide. Not for the casual reader.
,
257- Title
- Native American Ethnobotany
- Publication
-
- Author
- Moerman. D.
- Publisher
- Timber Press. Oregon.
- Year
- 1998
- ISBN
- 0-88192-453-9
- Description
- Very comprehensive but terse guide to the native uses of plants. Excellent bibliography, fully referenced to each plant, giving a pathway to further information. Not for the casual reader.
]. The seed is rather small and fiddly to utilize, it is enclosed in a dry papery hull[
207- Title
- The History and Folklore of North American Wild Flowers.
- Publication
-
- Author
- Coffey. T.
- Publisher
- Facts on File.
- Year
- 1993
- ISBN
- 0-8160-2624-6
- Description
- A nice read, lots of information on plant uses.
].
Medicinal
None known
Other Uses
None known
Propagation
Seed - sow spring in situ
If you have any useful information about this plant, please leave a comment. Comments have to be approved before they are shown here.
Useful Temperate Plants Database 2016 by
Ken Fern,
web interface by
Ajna Fern
with help from
Richard Morris.
