Comprehensive Description

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General: Lewis' mockorange, the state flower of Idaho, was named for Captain Meriwether Lewis, who collected the plant in 1806. Mockorange is a native, deciduous, erect to spreading shrub that grows to 3 to 10 feet tall. Showy white flowers occur in clusters of three to fifteen. It is extremely variable in vegetative and floral characteristics. Leaves are opposite, simple, ovate to elliptic-ovate, with entire to remotely dentate margins. Flowers are white, 1 to 1.4 inches across, with four petals. Fruit is a small dark brown capsule. Seeds are small, averaging 5,300,000 per pound. Roots are fibrous.

Distribution: Lewis' mockorange occurs in Washington, Oregon, Idaho, Montana and California in the United States. It also occurs in Alberta and British Columbia in Canada.

For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site.

Habitat: Lewis' mockorange occurs on well-drained, moist sites. It grows on deep, rich alluvial loams to rocky or gravelly loams. It is commonly found on rocky sites, at the base of talus slopes and cliffs, along streams, and seasonally moist draws. It is found at talus margins in the Columbia River Basin. It occurs at seeps, springs and rocky wet areas in the Crooked River National Grasslands in central Oregon.

Mockorange occurs from sea level up to 7,000 feet in the Cascade Range. Lewis' mockorange grows best on northern and eastern exposures.

Lewis' mockorange is tolerant of moderate shade. It is an early to mid-seral species, and is often present in seral shrub communities.

Mockorange tolerates fire and persists in forested environments where fire frequency is 5 to 45 years. It resprouts from adventitious buds in the root crown after top kill by fire.

Associated Species: Associates include alders (Alnus spp.), serviceberry (Amelanchier alnifolia), red-osier dogwood (Cornus sericea), beaked hazelnut (Corylus cornuta), hawthorns (Crataegus spp.), oceanspray (Holodiscus discolor), hollyleaved barberry (Mahonia aquifolium), ninebark (Physocarpus malvaceus), chokecherry (Prunus virginiana Oregon white oak (Quercus garryana), baldhip rose (Rosa gymnocarpa), willows (Salix spp.), poison-oak (Toxicodendron diversilobum) and others.


Public Domain

USDA NRCS Pullman Plant Materials Center, Pullman, Washington

Source: USDA NRCS PLANTS Database

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