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Betula lenta L.

Sweet Birch

Modern name

Betula lenta L.

A tree up to 70 or 80 ft high in a wild state; the bark of the trunk not peeling, dark, almost black; branchlets silky hairy when very young, soon becoming glabrous and shining brown. Leaves ovate or ovate-oblong, mostly heart-shaped at the base, pointed, 212 to 6 in. long, 112 to 312 in. wide, toothed (often doubly so), dark glossy green and ultimately glabrous above, paler green and silky-hairy on the midrib and veins beneath; veins in ten to thirteen pairs; leaf-stalk 14 to 1 in. long, hairy. Male catkins 2 to 3 in. long. Fruiting catkins 1 in. or rather more long, 12 in. in diameter, scarcely stalked; scales not downy, the lateral lobes rather wider than the middle one.

Native of eastern N. America, where it yields a valuable timber; introduced in 1759, according to Aiton. When bruised, the young bark has a sweet, aromatic taste and smell, and by distillation yields an aromatic oil. This birch is allied to B. lutea, but differs in the darker bark of the trunk, the sweeter-tasting young bark, and especially by the glabrous scales of the fruit catkin. In my experience it is not so well-doing a tree as B. lutea in this country.

It is not common in cultivation in the British Isles, but there are specimens 45 to 50 ft high at Tortworth, Glos.; Dawyck, Peebl.; and Mount Usher, Co. Wicklow, Eire.

Betula lenta

Betula lenta

From the Supplement (Vol. V)

This species has a more restricted distribution in the wild than its ally B. alleghaniensis (lutea), being rare in Canada and not extending beyond the Appalachians. By contrast B. alleghaniensis reaches as far to the north-west as the Great Lakes and some way beyond, and is well represented in south-eastern Canada.

specimens: Winkworth Arboretum, Surrey, 46 × 434 ft at 1 ft (1978); Hollycombe, Liphook, Hants, 62 × 634 ft (1984); Brocklesby Park, Lincs., 56 × 334 ft (1977); Tortworth, Glos., 56 × 334 + 314 ft (1979); Abbeyleix, Co. Laois, Eire, 52 × 4 ft (1985).

† B. uber (Ashe) Fern. B. lenta var. uber Ashe – Perhaps the rarest of all birches, this is known only from a single stand about one kilometre long and 100 metres wide, growing in the flood-plain of Cherry Creek, Smyth County, Virginia. It is allied to B. lenta but has smaller leaves on shorter petioles, shorter catkins, less pubescent and relatively longer-lobed bracts and smaller fruits. Fernald’s opinion that this species has some relationship with B. pumila is no longer accepted (Brittonia, Vol. 36, pp. 307-16 (1984); see also Castanea, Vol. 41, pp. 248-56 (1976)).

B. uber was introduced to the Royal Botanic Gardens, Wakehurst Place, Sussex, in 1984.



Other species in the genus