Plant of the Week
Tufted Wild Buckwheat (Eriogonum ovalifolium)
By Walter Fertig
With approximately 250 described species, the genus Eriogonum of the buckwheat family (Polygonaceae) is tied with Penstemon as the third largest genus of flowering plants in North America (after Carex with 480 species and Astragalus with about 375). The word Eriogonum is derived from two Greek words for woolly (erion) and knee (gony) in reference to the fuzzy-woolly enlarged nodes of Eriogonum tomentosum, the first Eriogonum to be described to science in 1803. Ironically, E. tomentosum is one of only three wild buckwheat species found east of the Mississippi River and is somewhat anomalous in the genus based on several floral characteristics. If Eriogonum were ever to be subdivided on stricter, evolutionary criteria, most species would fall into four segregate groups, Eucycla, Oregonium, Oligogonum, and Ganysma, with Eriogonum in the strict sense having just two species!
Nearly one-third of all recognized species and varieties of Eriogonum (in the broad sense) have limited distributions and are fairly rare. Such is not the case for tufted wild buckwheat (Eriogonum ovalifolium) which is one of our most abundant species and ranges across most of western North America from southern British Columbia and Alberta to northern Mexico. True to its Latin name, Tufted wild buckwheat can be recognized by its oval leaves (sometimes more elongated and spoon-shaped) which are borne in a dense, basal rosette. Flowers range from white to pink, red, or occasionally yellow and are clustered in a dense, ball-like head atop a long naked stalk (one variety is unusual in having a branched, umbel-like inflorescence). The species is extremely variable in flower color, leaf pubescence, leaf length, and overall height, and taxonomists recognize 11 different varieties. Overall, the species ranges from dry desert basins and sagebrush grasslands to montane meadows and alpine tundra.
Wild buckwheats have not traditionally been widely grown as ornamentals or used in wildland restoration. Studies by Susan Meyer and colleagues from the USDA Shrub Science Lab in Utah suggest that many Eriogonum species, including tufted wild buckwheat, are relatively easy to propagate from seed. Meyer found that about 25% of E. ovalifolium seed would germinate without a period of pre-chilling, while 100% germination occurred after 8 weeks of cold treatment. Besides being an interesting border or accent plant, tufted wild buckwheat and its relatives are highly drought tolerant and are important honey plants for native bees.