Tree to 17 m, dbh 45 cm, or more. Branchlets reddish brown or purplish grey and glabrous, with numerous lenticels. Leaves deciduous, deeply veined, 5–9 × 4.5–7 cm, obovate, upper surface dull green and glabrous or sparsely pubescent, lower surface white with some hairs on the veins and tufts of hair in vein axils, seven to nine lateral veins on each side of the midvein, margins deeply serrate, apex strongly emarginate; petiole glabrous or with sparse pubescence, 1.5–3 cm long. Staminate inflorescences catkin-like, 4–8 cm long; pistillate inflorescences solitary or in racemes of two to five. Cone woody, 1.3–1.7 × 1–1.2 cm, bracts 0.3–0.4 cm wide. Flowering May to June, fruiting November (Japan). Ohwi 1965. Distribution JAPAN: central and northern Honshu. Habitat Montane forest. USDA Hardiness Zone 5–6. Conservation status Not evaluated. Illustration NT142. Cross-reference B277, K137.
Bean (1976a) gave Alnus matsumurae a very short description, but this beautiful tree deserves more comment. It forms a good straight trunk bearing horizontally spreading branches that hold a solid canopy of foliage. The strongly veined, broadly rounded leaves are distinct by being conspicuously emarginate, although they can be merely truncate. The 17 m tree at Kew noted by Bean has gone, but there is a similarly sized one (16 m, dbh 45 cm in 2001) at Alice Holt, Hampshire (TROBI). At Stone Lane Gardens there is an 8 m specimen, planted in 2001. Alnus matsumurae is not common but seems to grow well throughout the British Isles, and probably also in much harsher conditions, although it may not always make a good tree. A shrubby specimen seen at the Morton Arboretum was received as wild-collected seed in 1995 from Arboretum National des Barres, France.