Common Hawthorn
Crataegus monogyna
Washington State Classification
Class C — Widespread, County-Selected Control
Plants can form thickets and block animal movement.
Quick Reference
Identification
Growth Habit
English hawnthorn is a long-lived, deciduous, small tree to large shrub. Its branches have sharp thorns and the leaves are deeply lobed. White flowers, which can have a pink tint, bloom in May and develop red fruits in the fall.
Leaves
Leaves are deciduous, alternately arranged and closely clustered on short shoots. Leaves are variable in shape and are mostly ovate (egg-shaped) to triangular in outline with 3 to 7 deep, sharp, lobes. The leaves are wide, leathery in texture, and can be glabrous (smooth and hairless) or hairy. Leaf edges are toothed, mainly near lobe tips.
Flowers
Flowers are clustered in groups of 10-20 on short stalks. Each has five septals and five white petals that age to a pinkish color. Five to twenty-five stamens with pink-purple anthers extend past the petals.
Fruit & Seeds
English hawthorn produces bright to deep red, drupe-like pome fruits that are elliptic to spherical in shape with one to two nutlets with one seed each found in each fruit.
Impact
Plants can form thickets and block animal movement. In fact, this plant was used historically used in hedgerows to contain livestock. Its dense growth can alter the structure of forest understories and open grasslands. Hybridization can occur between English hawthorn and the native hawthorn, Crataegus douglasii, altering the gene pool of the native species and creating competition for resources and pollinators. In Europe and New Zealand, Crataegus monogyna is a host of fire blight bacterium (Erwinia amylovora) which also affects pears and apples.
Ecology & Spread
Habitat
English Hawthorn grows in lowland areas on many soil types, growing best in moist soil or in areas with high precipitation, though established trees can survive moderate drought conditions. Please click here to see a county level distribution map of English hawthorn in Washington.
Spread Mechanisms
Reproduction
English hawthorn reproduces by seed. Fruit drops to the soil beneath the tree and is also dispersed by animals, primarily by the American robin.
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Control Methods
Biological Control
- There are not any approved biological control agents for English hawthorn. Its spines typically deter grazing.