Common buckthorn (Rhamnus cathartica)

Common Names: European buckthorn

Description: Produces a dense shade that suppresses growth of tree and shrub seedlings, and native herbaceous groundcover, reduces overall plant diversity; changes nutrient cycling by increasing nitrogen and carbon; had been widely recommended for conservation planting until invasive characteristics became apparent.

Habit: Deciduous; woody shrub to small tree ranging from 3-7.5 m (10-25 ft) in height and reaching 25 cm (10 in) in diameter.

Leaves: Simple, opposite to sub-opposite, oval, dark green in color, smooth and shiny, small teeth along margins, veins that curve from base towards leaf tip, leaf out early, long growing season.

Stems: One to several stems from the base; stems branch towards the crown; twigs with thorns often found near the tips; bark is brown to gray, peeling with age, dotted with vertical light-colored lenticels; inner bark is orange.

Flowers: Small, green-yellow, four-petaled, clustered in leaf axils, fragrant; bloom May to June.

Fruit and seeds: Fruit is a round, pea-size, black berry (on female plants only), persistent through the winter.

Habitat: Widely planted as an ornamental shrub in hedge rows; now found along roadsides, woodland edges, prairies, old fields; somewhat shade tolerant.

Reproduction: By prolific fruit and seed production, seeds widely dispersed by birds.

Similar species: Native alder-leaved buckthorn (Rhamnus alnifolia) is less than 1 m (3 ft) in height with dark scales on winter buds; non-native glossy buckthorn (Rhamnus frangula) has shiny entire leaves, always lacks terminal thorn.

Monitoring and rapid response: Monitor woodland edges and paths. Buckthorn leafs out early and retains its leaves late into fall. Begin control efforts in highest quality areas; hand pull or dig seedlings or small plants; target large, fruit-bearing plants for control/removal; foliar spraying may be effective for large populations where there are few natives present; treat cut stumps with herbicide as stumps sprout; basal bark treatment also effective. Where fuel is present, prescribed fire may provide effective control of seedlings in fire adapted communities.

Credits: The Michigan Natural Features Inventory (MNFI) has partnered with MISIN to provide the information in this fact sheet. Species images and/or information were used with permission from "A Field Identification Guide to Invasive Plants in Michigan's Natural Communities" and "A Field Guide to Invasive Plants of Aquatic and Wetland Habitats for Michigan.

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