California buckwheat (or flat-topped buckwheat, Eriogonum fasciculatum) is a prolific bloomer even in the long hot days of summer. The low, spreading shrub bears clusters of white to pinkish flowers, which become a conspicuous mahogany color in the fall. The small, narrow, rolled leaves resemble those of rosemary. This is not the buckwheat of pancake-fame, but it is an important nectar source for bees, and the resultant honey is delicious.
Other Common Names:
Eriogonum fasciculatum is native to California and is restricted to Western North America. Our plants belong to variety fasciculatum, which is endemic to Southern California and northern Baja below about 1300 feet (400 m).
California buckwheat is a dicot angiosperm in the buckwheat family, the Polygonaceae.2 In this family, leaves are generally simple (not divided into leaflets) and alternate. Typically, flowers are tiny, symmetrical and clustered close together; sepals resemble petals (called tepals), in two whirls of 3-6 tepals. Fruit is usually small, dry and 1-seeded.11,34,44
Other familiar Polygonaceae include rhubarb and sorrel.
With over 125 species, Eriogonum is the largest dicot genus in California.24 Four species have been reported from The Reserve. Others are slender buckwheat (E. gracile), long-stem buckwheat (E. elongatum), and bluff buckwheat (E. parvifolium).48
Our variety, var. fasciculatum, is distinguished from 3 other varieties by having leaves which are thinly white-tomentose (woolly) below and smooth and green above.2Jepson eFlora Taxon Page
The leaves of California buckwheat are small and leathery, the margins are rolled under (revolute), and the undersides are covered with fine hairs. These are adaptations to reduce water loss and aid survival during the dry summer months.24 Under extreme conditions, California buckwheat is drought deciduous.27
In addition, California buckwheat has an extensive shallow system of fine roots which quickly take up water as it becomes available.38
Buckwheat was an important medicinal plant for Native Americans. Kumeyaay (who called it Hamill) boiled flowers or leaves into a tea to be used as an eyewash, a mouthwash and a remedy for headaches, stomach aches and bladder infections.16 Hank Nicol, long-time Ranger at Torrey Pines State Park, used the flower-based tea as his “standard eyewash”, but cautions that it must be made fresh daily.32
The tiny seeds were gathered and ground into flour. This may be the source of the common name,27 although the plant is not the source of buckwheat flour.
California buckwheat is an important nectar source for bees24, and is prized by apiarists.
California buckwheat is one of the hosts of the parasitic dodder (or witch’s hair; Cuscuta californica).
Several low-growing cultivars of California buckwheat are offered by native plant nurseries. These make useful ground covers for the home garden.24