Sulphur-flower Buckwheat

Scientific Name: Eriogonum umbellatum Torr.

Sulphur-flower Buckwheat

General Information
Usda Symbol	ERUM
Group	Dicot
Life Cycle	Perennial
Growth Habits	Forb/herbShrub, Subshrub,
Native Locations	ERUM

Plant Guide

Alternate Names

Buckwheat bush, sulfur buckwheat, slender buckwheat, sulphur-flower buckwheat

Uses

Wildlife: The seeds are an important food source for many species of birds and small mammals. Quail, grouse, deer and mountain sheep eat the leaves. Landscaping: It can be used for environmental enhancement, erosion control and foundation plantings around mountain homes. It is an excellent dry flower for arrangements as it holds its color and structure for many months. Sulfur flower buckwheat plants withstand sun, heat, drought, and wind, making them ideal plants for dry sunny slopes. The showy flowers and seed heads, and compact growth habit make this plant a good choice for rock gardens. Bees produce a strong, dark honey from sulfur flower nectar. Ethnobotanic Uses: Modern knowledge of the ethnobotanical uses of Eriogonum is entirely attributed to Mexican and Native American herbal traditions. The Cahuilla used an infusion of the flowers as an eyewash, as well as for cleaning out the intestines, and made an infusion of the whole plant to shrink the uterus and reduce dysmenorrhea. Several California tribes used the tea to wash newborn babies. The Hopi used Eriogonum for hip and back pain, especially during pregnancy, and it was known to expedite birthing. Due to its water solubility and its lack of toxicity, Eriogonum can be taken as often as needed, and is safe to use in the last trimester of pregnancy as a diuretic to aid water retention.

Status

Please consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status (e.g. threatened or endangered species, state noxious status, and wetland indicator values). Brother Alfred Brousseau © St. Mary’s College of California @ plants.usda.gov

Description

Buckwheat Family (Polygonaceae), Sulfur flower buckwheat is a native, low-growing woody perennial commonly found on hot dry sunny exposures on rocky slopes and ridges throughout the west, It is native to western mountainous regions at elevations of 2,500 to 10,000 feet, Sulfur flower buckwheat requires well-drained sandy or gravelly soils with low fertility and will not tolerate saturated soils, The plant forms low, broad mats with individual clumps reaching one foot high to two feet across, Leaves are one inch long, shiny green on top and woolly underneath, Use soil moisture sensors to measure the soil moisture of Sulphur-flower Buckwheat., Flower stems 3 inches to 16 inches tall, are topped by clusters of tiny sulfur-yellow flower heads, Flowers range from yellow to orange or reddish, both in bloom and in mature seed heads, Flower displays can color entire slopes starting in June at lower elevations and continue into August at higher elevations,

Distribution

Sulfur flower buckwheat is found in dry, open and often rocky places. It is found in California to western Canada and also Colorado and New Mexico. This species has about thirty subspecies distributed across the western United States. For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site.

Adaptation

Sulfur flower buckwheat grows well in medium to coarse textured and well-drained soils.

Establishment

Sulfur flower buckwheat can be raised from seed or purchased as container grown plants at local nurseries. Collect the sharply angled small black seeds from dried flower heads by rubbing the papery dried flower heads between your fingers. They generally germinate without pretreatment and can be sown in spring or fall. However, the rate of germination is improved if they are first cold stratified. Cold stratify seeds by placing them in a plastic bag with moist peat moss or sand in a refrigerator three months. Plant out in the early spring. Seeds are naturally cold stratified by fall planting. Select a hot, sunny, well-drained planting site and broadcast the seeds directly on the ground where they are to grow permanently. Sulfur flower buckwheat seeds will germinate better if the seedbed has been cleared of weeds, and/or roto-tilled, or spaded to a depth of eight to ten inches, and mixed with additional compost. Scatter seeds evenly over the seedbed and rake and water lightly. Cover seeds with sand or weed-free compost to a depth equal to one or two times the seed diameter (about one eighth inch). Keep the seedbed moist by sprinkling two to three times daily until seeds germinate. After the seeds germinate, continue to water once every two to three days for the next few weeks; then once a week for another month. Continue to water a few times a month through the fall. Plants are drought tolerant when established and will need only occasional watering. Sulfur flower buckwheat blooms the second year from seed. It can be pruned back after flowering to promote a denser, more compact plant. Sulfur flower buckwheat has a long taproot and thus mature plants are difficult to transplant. When container-grown plants are ready to plant, dig a hole two to three times the diameter of the root ball and at least six inches deeper. Backfill the hole with six inches of native soil. Make a few one-eighth inch deep vertical cuts in the rootball, or carefully loosen roots away from the rootball with your hands to encourage roots to grow into the new soil. Set the plant into the hole and fill in around the roots with planting mix, firming the soil with your hands as you fill, until the hole is half full. Fill the hole with water and allow it to settle. This will settle the soil and eliminate air pockets around the roots. Backfill with enough soil so that the plant will set at the same level at which it was growing in the container. Water it to allow the soil to settle, then add more soil if necessary. Build a berm of soil to form a watering basin around the outer edge of the hole. Break the basin down after two or three years.

Management

Control of weeds and irrigation is necessary in the first year of establishment.

Seeds and Plant Production

Plant Production

Plant Production

Sulfur flower buckwheat is grown at the Lockeford Plant Materials Center for foundation seed production. The field was established with transplants and has produced an average of 150 pounds of seed per acre. Seed has been vacuumed or hand harvested in June-July and does not shatter easily. Germination has averaged about 35 percent with varying amounts of seed and seed rapidly loses viability within a few years. There are about 140,500 seeds per pound. Cultivars, Improved, and Selected Materials (and area of origin) ‘Sierra’ Cultivar: Sierra was collected from native plants on August 23, 1972 at South Lake Tahoe, California. The original collection was increased at Lockeford through seed and plants. It is a low growing shrub found on dry slopes and ridges, 1,200 to 10,000 feet. The gray-green leaves are ovate, smooth above and finely hairy beneath. Plants are 8 to 12 inches high, spreading up to 2 feet in diameter. Yellow flowers in umbels erect or ascending from a woody base, turn orange red at maturity. Flowers are used in dry flower arrangements.

Fact Sheet

Alternative Names

Alternate Common Names: Sulphur flower, buckwheat bush, sulfur buckwheat, sulfur flower buckwheat, sulphur wild buckwheat, slender buckwheat Alternate Scientific Names: There are 20 to 40 recognized botanical varieties of Eriogonum umbellatum, many of which intergrade across their ranges.

Uses

Wildlife & Livestock: The seeds are an important food source for many species of birds and small mammals. Quail, sage-grouse, deer and mountain sheep eat the leaves, and insects found on the plants are an important food source for sage-grouse chicks. The plants are rated as having medium palatability for browse animals, but low palatability for grazing animals, with low protein content. Pollinators: Sulphur-flower buckwheat attracts a wide variety of bees and other native pollinators. It is a larval host and nectar source for lupine blue butterfly (Plebejus lupini). The cythera metalmark butterfly (Apodemia mormo cythera) and the Rocky Mountain dotted-blue (Euphilotes ancilla) are also found in association with a few varieties of sulphur-flower. Bees produce a strong, dark honey from the nectar. Restoration: Sulphur-flower buckwheat can be included in seed mixes for restoration of native plant communities on dry, rocky slopes and other sites where the species is adapted. Landscaping: Sulphur-flower buckwheat can be used for environmental enhancement, erosion control and foundation plantings around homes. Plants withstand sun, heat, drought, and wind, making them ideal for dry sunny slopes. The showy flowers and seed heads, and compact growth habit make this plant a good choice for rock gardens. Ethnobotany: Tribes throughout western North America traditionally used different parts of the sulphur-flower buckwheat plant to treat a variety of ailments. The Klamath used a poultice of the leaves to soothe burns. The Cheyenne made a tea from powdered stems and flowers that was used as a gynecological aid for lengthy menses. The Paiute and Shoshone made a poultice of mashed leaves, and sometimes roots, to treat lameness or rheumatism, and took a hot decoction of roots for colds or stomachaches. The Kayenta Navajo used the plant as a fumigant or to induce vomiting for gastrointestinal ailments. The Kawaiisu used the mashed flowers as a salve for gonorrheal sores.

Status

Please consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status (e.g., threatened or endangered species, state noxious status, and wetland indicator values).

Description and Adaptation

Adaptation

Adaptation

Sulphur-flower buckwheat is a native, low-growing, woody perennial in the buckwheat family (Polygonaceae). The plant typically forms low, broad mats with individual clumps ranging from 4 inches to 2 ft (but up to 4 ft) tall and wide. Leaves are basal, 1 inch long, and softly wooly or hairless. Flower stems are 3 to 16 inches tall and topped by umbel-shaped clusters of tiny flowers. Flowers range from sulfur yellow to orange or reddish, sometimes turning rusty orange-red with age. Floral displays can color entire slopes starting in June at lower elevations and continue into September or October at higher elevations. Sulphur-flower buckwheat is usually found in dry, open, rocky sites with shallow, sandy soils, especially on sunny slopes and ridges. This species typically grows in regions that receive from 8 to 18 inches annual precipitation, which may come in the form of winter rain/snow or summer monsoons. This plant grows best in full sun on well-drained, sandy or gravelly soils with low fertility, but will sometimes tolerate saturated soils and light shade. It has high drought, salinity and carbonate tolerance, and grows in soils ranging from a pH of 6.5 to 9.0. Sulphur-flower buckwheat is native to western mountainous regions of North America at elevations of 700 to 12,000 feet. It is found from western Canada south to California and east into Colorado and New Mexico. For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site. Sulphur-flower buckwheat distribution from USDA-NRCS PLANTS Database. Establishment and Seed

Production

For most uses, sulphur-flower buckwheat can be established by direct seeding or transplanting plugs or container stock. Select a sunny, well-drained planting site and maintain good weed control, especially of annual grasses, during the first year of establishment. The recommended single-species broadcast seeding rate is 8 to 10 pounds per acre, but the rate should be adjusted depending on the species mix and site conditions. There are 100,000 to 200,000 seeds per pound, so a seeding rate of one pound per acre will result in about 2 to 5 seeds per square foot. Seeds should be raked in to a depth of about ¼ inch. Seeds are dormant, and usually require 8 to 12 weeks (but as many as 24 weeks) of cold, moist stratification in order to germinate, depending on the elevation and climate of the original collection. Dormancy is broken naturally by fall sowing if locally-adapted germplasm is used. Alternately, seeds can be cold stratified by placing them in a fine mesh bag buried in moist peat moss or sand in a ventilated container at 34 to 37°F and planted out in the early spring. For seed production prepare a weed-free, smooth, firm, level seedbed for planting. At the Corvallis Plant Materials Center, fields are direct sown in the fall at a depth of ¼ inch and a rate of 10–12 pounds per acre (50 seeds per square foot) in rows 18–24 inches apart, unless wider row spacing is needed for between row cultivation. Weeds are controlled by row tillage, hand removal, and spot treatments with a nonselective herbicide. Production fields can also be established in the fall to early spring from container stock transplanted into weed mat to reduce the need for weed management. Plants do not produce seed until their second growing season and do not reach full production until year three, but can remain productive for ten to twenty years. Seeds are mature when the petals and sepals become dry and papery (June to July in California and Oregon). Seed does not shatter easily and will remain on the plant for a few weeks following maturation. Small plots are harvested by hand with rice knives, while larger plots can be harvested with a seed stripper. Seeds are brittle and can be damaged easily when using threshers or combines. Use a hammermill or a gentle brush machine to break the seeds from the stalks and bracts, followed by a small air-screen machine to remove chaff and weed seeds. Seed yields vary from 150 to 700 pounds per acre.

Management

Weeds should be controlled and irrigation may be necessary in the first year, but plants are drought tolerant once they are established, Use soil moisture sensors to measure the soil moisture of Sulphur-flower Buckwheat., Plants can be pruned back after flowering to promote a denser, more compact plant,

Pests and Potential Problems

Plants are relatively free from disease and pest problems, but are susceptible to root and crown rot when grown on poorly drained soils.

Environmental Concerns

There are no known environmental concerns associated with sulphur-flower buckwheat. Cultivars, Improved, and Selected Materials (and area of origin) Sulphur-flower buckwheat seeds and container plants are readily available from commercial sources. ‘Sierra’ (California) is a cultivar that was developed for erosion control and landscaping on dry, rocky slopes and droughty sites. This cultivar is adapted to the dry Sierra Nevada foothills and mountains where soils and slopes limit competition.

Prepared By

Annie Young-Mathews, Conservation Agronomist USDA NRCS Corvallis Plant Materials Center, Oregon

Plant Traits

Growth Requirements

Morphology/Physiology

Reproduction

Suitability/Use

Sulphur-flower Buckwheat

Sulphur-flower Buckwheat