Physocarpus capitatus - pacific ninebark

Family: Rosaceae
Wetland Indictor Status: FACW-

General Species Description

This deciduous shrub is erect and somewhat spreading, growing to 4 meters tall. The large branches (5 mm in diameter) are heavily ridged on both sides and when mature have light brownish-red shredding bark. The common name is derived from the belief that there are nine layers of shredding bark on the stems.


The deciduous leaves are simple, alternate, toothed, broadly rounded at the base, palmately 3-5 lobed (usually 3), deeply veined, and 3-8 cm long. They are dark green and shiny above and lighter underneath with many star-shaped hairs. The reddish-orange petioles have stipules. The leaves turn bright yellow with reddish-orange margins in the fall.


Many dense, terminal, rounded inflorescences are very distinctive from a distance. The perfect flowers are small, creamy-white, 5-lobed, with 20-40 pink stamens and 3-5 pistils.


The fruits are arranged in dense, reddish-brown bunches of 3-4 woody follicles which are 0.6-1 cm long. Each follicle has two to many yellowish, shiny seeds. The scientific name comes from the Greek physa, meaning 'bellows or bladder', and carpos, meaning 'fruit', referring to the inflated appearance of the fruits.


Pacific ninebark prefers moist to wet places such as stream banks, swamps, lake margins, coastal marshes and moist woods. It is also found at the edges of woods and meadows in nitrogen-rich soils or in mineral, alluvial soils. It can be found in drier, semi-open or open habitats, as it is tolerant of water table fluctuations. This species is often found in association with redstem dogwood (Cornus sericea) and salmonberry (Rubus spectabilis).


This shrub is found in the western Cascades, from Alaska to California, and also in northern Idaho. It's range is limited on the north Pacific Coast.

Similar Species

The lobed leaves of pacific ninebark can often be confused with those of other species. The key when identifying this species is to look at more features than the leaves alone, if possible. Thimbleberry (Rubus parviflorus) has much larger 5-lobed leaves and raspberry-like fruits. Salmonberry (Rubus spectabilis), found in similar habitats, has similar shredding bark, but has pinnately compound leaves and single magenta flowers and orange berries. Oceanspray (holodiscus discolor) has similar alternate, pubescent leaves, which are more often coarsely toothed than lobed; dense, terminal pyramidal inflorescences; and hairy achenes. The foliage of Ribes species, especially R. viscosissimum (sticky currant) and R. sanguineum (red currant) may also be confused with that of pacific ninebark, but all Ribes species have berries for fruit, thorns or spikes, and often have smaller, smooth-surfaced leaves. Highbush cranberry (Viburnum edule) also has 3-lobed leaves, but they are much larger, and have opposite a rrangement. Mallow bark (Physocarpus malvaceus) is common in the drier habitats of our region. This shrub is smaller than Pacific ninebark and has hairy fruit capsules.

Ecological Value

The twigs, bugs and foliage of pacific ninebark are browsed by herbivores.

Human Value

Native northwest peoples used the wood for making toys and knitting needles. The Coast Salish, Nuxalk and Kawkwaka'wakw peoples also used a tea made from peeled pacific ninebark branches to treat constipation, upset stomach, gonorrhea and sores on the neck. The bark is believed to be toxic and should not be eaten. Pacific ninebark is sometimes used as an ornamental shrub.


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Hitchcock, C. L. and A. Cronquist. 1973. Flora of the Pacific Northwest. University of Washington Press, Seattle WA, 730pp.

Parish, R., R. Coupe and D. Lloyd. 1996. Plants of Southern Interior British Columbia. Lone Star Publishing, Vancouver, BC, 463pp.

Pojar, J. and A. MacKinnon. 1994. Plants of Coastal British Columbia. Lone Star Publishing, Vancouver, BC, 527pp.

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This page was created by: Tasha Murray, August 2000

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