Sitka mountain-ash is not a true ash but a shrub in the rose family. It usually grows 4 to 8 feet tall with several stems, though it can become a small tree, and on rocky alpine ground it may stay only a foot or two high. Its leaves are divided into 7 to 11 leaflets, which gives the branches a soft, feathery look.
In early summer it carries round-topped clusters of small white flowers. By fall these become bunches of red fruits about 0.4 inch long with a bluish, waxy bloom. The fruit hangs on into late winter, so it feeds wildlife when little else is available. Songbirds, upland game birds and small mammals eat it and spread the seeds, bears eat the fruit, leaves and stems, deer browse the twigs and elk use it in summer.
The plant needs sun. It does poorly under a closed canopy but persists in clearings, and it is one of the shrubs that moves into openings from seed carried in from elsewhere.
On Mt. Hood, watch for it in forest openings, along trails and on rocky slopes at middle to high elevations. Fall, when the red fruit clusters show, is the easiest time to pick it out.
How to identify it
A multi-stemmed shrub with pinnate leaves of 7 to 11 oblong leaflets that have rounded tips and sharp teeth only along the outer half or less. Winter buds are reddish with rusty hairs. Round-topped clusters of white flowers become clusters of red fruit with a bluish, waxy bloom.
Look-alikes
Cascade mountain-ash (Sorbus scopulina) grows in similar places. Its leaflets are more pointed and finely toothed nearly the whole length, its buds are shiny with whitish hairs or none, and its fruit is a glossy orange to scarlet.
Habitat
Forest openings, clearings and open conifer forest at middle to high elevations, especially about 3,000 to 5,000 feet on the west slope of the Cascades. It favors well-drained, sunny sites and also grows low and compact on rocky alpine ground.
Sightings in the forest
482 research-grade sightings in Mt. Hood National Forest on iNaturalist, most recently on September 26, 2026. See them on iNaturalist →