Missouri Invasive Plant Council

Common buckthorn (Rhamnus cathartica) is much more of a problem north of Missouri; nonetheless, it is gradually increasing in central and eastern Missouri. Early detection and control are critical in reducing its spread, impact, and abundance.

Common buckthorn is a many-branched, shrubby tree with a spreading, irregular crown. Leaves are simple, some appearing alternate, but most are opposite, egg-shaped, abruptly pointed (sometimes rounded) at the tip, and finely toothed. Both upper and lower surfaces are smooth. Leaves have 3–5 pairs of veins branching from the midvein that curve along the edges of the leaf. Leaves appear early in spring and are retained late into autumn. Trunk diameter to 10 inches. The terminal bud is often modified into a spine. Flowers have 4 small, yellowish green petals and appear in clusters from April to June; male and female flowers usually produced on separate plants. Fruits appear August–September, often remaining until December. Fruits are round, black, small (up to ¼ inch in diameter), juicy, and typically contain 3–4 seeds.

NOTE: There are several native species of buckthorn in Missouri.