The Genus Crataegus
1. Columbia Hawthorn: Crataegus columbiana ??? - Large shrub or small tree to 18 feet. Branches have numerous stout thorns, some up to an inch in length. White flowers are small, less than dime size, but clustered in groups of 5 to 30. The flowers have 5 petals each. The leaves are simple, and variable in shape, some lobed and others with toothed edges only at the tip of the leaf.
2. Douglas Hawthorn, Black Hawthorn: Crataegus douglasii (formerly C. douglasii var. douglasii) - Big, coarse shrub or small tree up to 12 meters high with rough, scaly, brown bark. Young branches dark red-brown. Thorns 12-25 mm long. Leaves 25-75 mm long, broadly obovate, double-toothed above the base. Flowers usually many in flat-topped corymbs. Flowers about 15 mm wide with short triangular sepals. Petals white and orbicular in shape. Stamens number 10 with pink anthers.
3. Suksdorf's Hawthorn: Crataegus suksdorfii (formerly C. douglasii var. suksdorfii) - Small tree or big shrub. Small branches pale grayish brown and thorns stout, 8-12 mm long. Leaves similar to variety douglasii but narrower. Flowers 12-15 mm wide with 15-20 stamens.