Alderleaf buckthorn, American alder-buckthorn, dwarf alder, nerprun á feuilles d'aulne Alderleaf buckthorn, American alder-buckthorn, dwarf alder, nerprun á feuilles d'aulne

Shrubs, 0.5–1(–1.5) m, unarmed. Branchlets gray to brown, glabrous or pubescent. Leaves deciduous, alternate; petiole 5–15 mm; blade dark green to olive green on both surfaces, lanceolate-oblong to elliptic or lanceolate-ovate, 4.5–11 cm, herbaceous, base cuneate to rounded, truncate, or subcordate, margins crenate to crenate-serrate, apex obtuse to acute or acuminate, abaxial surface glabrous or puberulent along veins, adaxial surface glabrous or glabrate; secondary veins (4–)5–7 pairs, all diverging at nearly same angle. Inflorescences fascicles or flowers solitary. Pedicels 2–10 mm. Sepals 5. Petals 0. Drupes black, globose or slightly elongate, 6–8 mm; stones 3.

Flowering May–Jul. Fens and swamps, generally calcareous, riparian thickets, interdunal swales, shore lines, marshes and mats, wet meadow edges, outcrops, deciduous and coniferous forests; 10–2700 m; Alta., B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.S., Ont., P.E.I., Que., Sask.; Calif., Conn., Idaho, Ill., Ind., Iowa, Maine, Md., Mass., Mich., Minn., Mont., N.H., N.J., N.Y., N.Dak., Ohio, Oreg., Pa., R.I., S.Dak., Tenn., Utah, Vt., Va., Wash., W.Va., Wis., Wyo.

Rhamnus alnifolia is a primary host for the soybean aphid.