About Sidalcea campestris Greene
Sidalcea campestris, commonly called meadow checker-mallow, is a taprooted perennial herb that grows from thick, stubby rhizomes. It produces a basal rosette of toothed leaves, with erect, hollow stems. It bears numerous five-petaled flowers, typically fifty or more per plant, arranged in branched racemes at the top of stems. Flower colors range from white to pink. This species prefers moist, well-drained to dry soil, and grows in locations with full sun to part shade. It occurs in grassy meadows, unplowed fields, and along roadsides in Oregon's Willamette Valley. Historically, it was native to Benton, Clackamas, Douglas, Lane, Linn, Marion, Multnomah, Polk, Washington, and Yamhill counties in Oregon. Today, it is only found in the central portion of its historic range, and is locally common in the Salem area. It has not been recorded growing at elevations above 250 meters. Sidalcea campestris is a plant of conservation concern listed by the Oregon National Heritage Program, but it is not currently classified as threatened or endangered. It is uncommon in the wild; because many of its populations grow along fences and roadsides, it is vulnerable to damage from herbicide spraying. Another conservation concern is its small historic range. This species is an important part of pollinator habitat in the Willamette Valley. Its flowers are a high-quality source of nectar and pollen for native bees, wasps, flies, and butterflies. It provides nectar and/or pollen to the endangered Fender's Blue Butterfly (Plebejus icarioides fenderi), as well as the native solitary bee Diadasia nigrifrons. Diadasia nigrifrons are oligoleges, meaning they are specialist bees that depend on pollen and nectar from only a small number of plant species. Analysis of pollen loads from wild Diadasia nigrifrons shows that these bees collect pollen exclusively from plants in the genus Sidalcea. Only three native Sidalcea species are found in the Willamette Valley, making Sidalcea campestris critical to the continued survival of Diadasia nigrifrons. As an ornamental plant, Sidalcea campestris is attractive and blooms from June to August. It can be grown easily from seed, by dividing mature plants, or by transplanting plugs. It grows in full sun to part shade, reaching up to 2 feet wide at maturity. Its flowering stems can grow 2 to 6 feet tall. It is highly drought tolerant, and can tolerate seasonally dry soils.
