Synonyms: Crataegus columbiana , Crataegus columbiana var. piperi, Crataegus piperi
Columbia hawthorn is a coarse shrub with arching branches or a small tree up to 5 meters high. The small branches are medium brown in color with strong, long straight or recurved thorns from 4-7 cm long (as long as the leaves!). The leaves alternate on the branches and are simple with pinnate venation. They have short petioles, are 2.5-6 cm long, and are obovate in shape, with the margins varying from double toothed to shallowly lobed with divergent teeth.
The inflorescence is a flat or convex corymb. Individual flower are 1.5 cm wide with 5 white petals which are broadly obovate. The stamens normally number 10, but may also number fewer than that. The fruit is red, ovoid, and about 1 cm long.
Columbia hawthorn is found in meadows, on dry hillsides, and in riparian areas.
Columbia hawthorn may be found from southern British Columbia south along the eastern edge of the Cascades to California. It may be found eastward to Alberta and south to Idaho and Montana.
In the Columbia River Gorge, it may be found near an elevation of 200' at Horsethief Butte State Park and about 3 miles west of Irrigon, OR.