Northern Prairie Wildlife Research Center
BUCKTHORN FAMILY (Rhamnaceae)
IND. STATUS: [FAC-]
FIELD CHARACTERISTICS: A shrub or small tree growing to 6 m. in height. Some branches end in short thorns. Leaves mostly opposite or subopposite, with some alternate. Leaves broadly elliptic, oblong, or elliptic-oblong, 3-6 cm. long, with a margin of fine teeth. Lateral leaf veins (2) 3 (4) on each side, strongly, upcurved. Plants are dioecious (unisexual) with female plants producing black fruit, 5-6 mm. thick, commonly with 4 stones (hard seeds). Flowers appear with the leaves and have parts in 4s.
ECOLOGICAL NOTES: Introduced from Eurasia and planted as an ornamental, common buckthorn is an aggressive invader of both upland and wetland habitats becoming a noxious weed. Some may consider it the "purple loosestrife of shrubs" for this reason. Birds eat the fruit and spread the seeds such that even scientific and natural area quality fens, prairies and woodlands now have infestations of buckthorn. Common buckthorn can form dense thickets that shade out species of sedge meadows, calcareous fens and the spring ephemerals of woodlands. It is especially prolific in drained peatlands and upland oak forests. Also see comments under glossy buckthorn (R. frangula).
SOURCE: Gleason and Cronquist (1991); Voss (1985).