Glossy Buckthorn (Invasive Plant found in MA)

Glossy Buckthorn

Frangula alnus

Summary ⁷

Rhamnus frangula, (Frangula alnus), the alder buckthorn, is a tall deciduous shrub in the family Rhamnaceae. It is native to Europe, northernmost Africa, and western Asia, from Ireland and Great Britain north to 68°N in Scandinavia, east to central Siberia and Xinjiang in western China, and south to northern Morocco, Turkey, and the Alborz and Caucasus Mountains; in the northwest of its range (Ireland, Scotland), it is rare and scattered. It is also introduced and naturalised...

Description ⁸

Shrubs or small trees, rarely to 7 m tall. Young branches greenish, sparsely puberulent; older branches brownish, with distinct transversely oriented lenticels. Petiole 1-1.9 cm, puberulent, ± glabrescent; leaf blade abaxially pale green, adaxially green, broadly elliptic or oblong, rarely obovate, 4-11 × 2.5-6 cm, papery, abaxially sparsely puberulent on midvein, adaxially glabrous, lateral veins 6-10 pairs, prominent on both surfaces, base broadly cuneate or subrounded, margin entire, apex shortly acuminate or rounded, rarely acute. Flowers solitary or 2-4-fascicled at leaf axils, glabrous. Pedicels 5-10 mm. Sepals keeled and slightly rostrate adaxially. Petals orbicular, apex slightly emarginate. Disk thin, lining calyx tube. Ovary globose, 2- or 3-loculed; style undivided; stigma slightly 2- or 3-lobed. Drupe red, turning purple-black at maturity, 6-8 mm in diam., with 2 or 3 lenticular stones; fruiting pedicel 7-10 mm. Fl. Apr-Jul, fr. Jun-Sep. 2n = 20.