Eriogonum is a genus of flowering plants that belongs to the family Polygonaceae and is commonly referred to as wild buckwheat. This genus contains more than 250 species, including a few wildflowers that are common in North America. Some plants in this genus differ greatly in appearance, and studies indicate that new species are still occurring naturally. Many moths and butterflies use these plants as a source of food. Due to how heavily some insects rely on Erigonum for food, it is speculated that an entire family of insects may become endangered if the plant dies out.
Some species, such as Eriogonum alpinum, are rarely seen in the wild and therefore considered endangered as of 2010. For the most part, however, the genus is thriving so well in many parts of the United States, especially California, that it is considered a weed. Though considered a weed, it is not considered invasive, so there are no efforts to hinder its growth as of 2010.
While many of the plants differ wildly in appearance, some of them can be identified by a tall stem with an inflorescence lined with pink, yellow, or white flowers. These stems are around 1 foot (0.3 m) tall and covered in woolly fibers, supporting leaves around the base. Some species have stems that are rarely erect; instead, they droop or lie on the ground. Most plants belonging to the genus do not grow taller than 2 feet (60 cm), though 1.5 feet (40 cm) is far more common for an adult plant.
One species, Mount Diablo buckwheat or Eriogonum truncatum, was considered extinct, as the last recorded sighting took place in the mid-1960s. In 2005, after much searching, the plant was sighted once again. The rediscovery is credited to a University of California, Berkeley, graduate who was conducting a floristic study on Mt. Diablo before suddenly realizing he was surrounded by the supposedly extinct Mount Diablo buckwheat. There was much media coverage over this discovery, and restoration programs were in progress as of 2007. The plant was still considered critically threatened as of 2010.
In general, Eriogonum is considered an easy plant to cultivate. It adapts to varying conditions and does not require very wet soil. The plants grow very fast and have many uses, including crop rotation to improve soil and smother weeds. As of 2010, the demand for buckwheat plants in the United States, Russia, and Japan was growing. Japan primarily uses the plants as flour to make noodles, though Russian and American people often use the flour for breakfast cereals.