How Soil Influences the Rarity and Evolution of Wild Rare Buckwheats

The genus Eriogonum, also known as the Wild Buckwheats, is one of the largest and most diverse genera in North America. An estimated one-third of the roughly 250 species in this genera are considered uncommon or rare, and a total of fourteen taxa have been listed as either endangered, threatened, or are candidates for listing under the Endangered Species Act. Many species in this genus are specialized to particular soil types making them “edaphic endemics.” To help you better understand the dynamics of species rarity and edaphic endemism, we’ll look at three currently listed Eriogonum species: Steamboat buckwheat (Eriogonum ovalifolium var. williamsiae); Tiehm’s buckwheat (Eriogonum tiehmii); and Umtanum desert buckwheat (Eriogonum codium).