Polygonaceae
Polygonaceae Scientific classification Kingdom: Plantae Division: Magnoliophyta Class: Magnoliopsida Order: Polygonales Family: Polygonaceae Genera Afrobrunnichia[?] Antigonon[?] Aristocapsa[?] Atraphaxis[?] Brunnichia[?] Calligonum[?] Centrostegia[?] Chorizanthe[?] Coccoloba[?] Dedeckera[?] Dodecahema[?] Emex[?] Eriogonum[?] Fagopyrum[?] Fallopia[?] Gilmania[?] Goodmania[?] Gymnopodium[?] Harfordia[?] Hollisteria[?] Knorringia[?] Koenigia[?] Lastarriaea[?] Leptogonum[?] Muconea[?] Muehlenbeckia[?] Nemacaulis[?] Neomillspaughia[?] Oxygonum[?] Oxyria[?] Oxytheca[?] Parapteropyrum[?] Persicaria Podopterus[?] Polygonella[?] Polygonum[?] Pteropyrum[?] Pterostegia[?] Rheum[?] Rumex[?] Ruprechtia[?] Stenogonum[?] Symmeria[?] Systenotheca[?] Triplaris[?] Ref: Families of Flowering Plants (http://biodiversity.uno.edu/delta/angio/www/polygona.htm) as of 2002-11-15 This family contains buckwheat, sorrel (but not wood sorrel[?]), rhubarb, and knotgrass[?]. It is named for the shape of the seed; that of rhubarb, for example, has a triangular cross-section.