Home to the plants of the Sonoran, Chihuahuan and Mojave Deserts
Polygonaceae, Buckwheat Family
In North America Polygonaceae or the Buckwheat Family is well represented with more than 30 genera and over 780 accepted taxa. Species are found throughout all of North America and northern Mexico.
Worldwide according to the Plant List, Polygonaceae includes almost 60 genera and approximately 1,380 accepted species names. By far the 2 largest genera include Eriogonum with over 250 species and Polygonum with more than 200 species.
Polygonum is found throughout North America and Greenland while Eriogonum also occurs throughout North America. In the United States some members of this family are often referred to as knotweeds and smartweeds. Other large North American species include Rumex with almost 60 species and 75 accepted taxa overall and the genus Chorizanthe has 33 species with 51 accepted taxa overall.
As far as important economic species go, Polygonaceae contain some of the most notorious weeds, including species of Persicaria, Emex, Rumex, and Polygonum, such as Japanese Knotweed. Some species in the Buckwheat Family are cultivated as ornamentals. The genus Triplaris is known for its lumber production. Coccoloba is a genus of approximately 200 species native to the tropical and subtropical regions of the Americas, in South America, the Caribbean and Central America. Two species extend to Florida and one species, native to south Florida, Coccoloba uvifera (Seagrape and Baygrape) has fruits that are made into jelly and commercially sold. Seeds of Fagopyrum are made into a dark flour and the stems (petioles) of Rhubarb (Rheum rhabarbarum) are eaten as a bitter food item; leaves of common sorrel (Rumex acetosa) are used as a garnish in salads.
In Arizona the largest genera include Polygonum, Eriogonum and Rumex.