Polygonaceae
- Botanical characteristics of this family with illustrations of several species.
- http://delta-intkey.com/angio/www/polygona.htm

Close-up View of Common Knotweed, Common Lamb’s-quarters and Sheep Sorrel
- Photographic study by Brian Johnston of these three species, Polygonum arenastrum, Chenopodium album and Rumex acetosella.
- http://www.microscopy-uk.org.uk/mag/artaug07/bj-small.html

Polygonaceae (Buckwheat Family)
- Information on this family and a photograph and description of Coast Buckwheat (Eriogonum latifolium), Sheep Sorrel (Rumex acetosella) and Curly Dock (Rumex crispus).
- http://plants.montara.com/ListPages/FamPages/Polygona.html

The Polygonaceae
- Description of the family, which are herbs, shrubs, or rarely trees comprising about 30 genera and 1,000 species. Includes photos of a few examples.
- http://www.botany.hawaii.edu/faculty/carr/polygon.htm