A tree 20 to 30 ft high in Britain, but occasionally over 40 ft high in a wild state; branches slender, the lower ones pendulous, forming in the open a wide-topped, rounded head. Leaves ovate or oval, rounded or heart-shaped at the base, pointed, saw-toothed, 11⁄2 to 3 in. long, 1 to 13⁄4 in. wide; both surfaces clothed with white hairs when they expand, soon becoming quite glabrous and of firm texture. Flowers pure white, produced in April (usually when the leaves are less than half their full size), in erect clusters 2 to 3 in. long, terminating short lateral twigs; petals obovate or strap-shaped, 1⁄2 to 3⁄4 in. long, 1⁄4 in. wide. Fruit ripening in June, orange-shaped, 1⁄4 to 1⁄3 in. wide, changing from green to red, finally to black-purple, dry and tasteless.
Native of the eastern and central United States from Maine to Florida and westward to Minnesota and Louisiana; owing to the confusion between this species and A. laevis the date of introduction is uncertain, but one or the other was introduced in 1746. From the time of the ripening of the fruit it is often called ‘June-berry’. There are few more delightful small trees than this when seen at its best, which, at Kew, is usually about the second week in April; the whole tree then becomes sheeted with white. Unhappily, it is a very fleeting beauty, lasting, as a rule, less than a week. Its autumn beauty is more durable, and it is then one of the most striking of hardy trees, the foliage changing before it falls to a rich soft red; in some forms, however, to a clear bright yellow or orange-scarlet. See also A. laevis.
The name A. canadensis has had a chequered history. By early botanists it was used in a very wide sense, which included both A. arborea and A. laevis, as well as other related species. After the publication of Wiegand’s monograph (1912) the name A. canadensis (L.) Med. was restricted to the species described above, but in 1941 Fernald (Rhodora, Vol. 43) pointed out that the Mespilus canadensis of Linnaeus is in fact the species which had been known as A. oblongifolia Roem., and it is for that species, which is rare in gardens, that the name A. canadensis (L.) Med. must be used. For the amelanchier described above, which is the A. canadensis of Rehder’s Manual etc., the correct name under the rules of botanical nomenclature is A. arborea.
From the Supplement (Vol. V)
A tall shrub with ascending main stems, or a tree up to 40 ft or even more high. Leaves from ovate to slightly obovate, acuminate at the apex, rounded to heart-shaped at the base, saw-toothed, 1[1/2] in. to 4 in. long, 1 to 2 in. wide, densely white-woolly beneath at flowering time, when they are folded and quite small, and still slightly hairy beneath even when mature. Flowers pure white, borne in late April in racemes up to 3 in. long. Petals spathulate to strap-shaped, up to about [5/8] in. long. Calyx-tube glabrous on the outside. Sepals triangular, soon reflexing. Top of ovary glabrous. Fruits ripe in June, dry and tasteless, reddish purple.
A native of North America from south-east Canada to northern Florida in woodland and thickets; described by the younger Michaux in 1810 as Mespilus arborea, but until quite recently either treated as a variety of A. canadensis or considered to be synonymous with it. It was not recognised as a distinct species under its present name until 1945; see further under A. canadensis.
A. arborea is the tallest of the amelanchiers, and there are many specimens up to 36 ft high and 3 ft in girth in the Arnold Arboretum, Massachusetts. A tree in Michigan has been recorded as 76 ft high (Richard E. Weaver, Arnoldia, Vol. 40, pp. 94-7).
An amelanchier growing at Syon Park, London, 40 ft high in about 1847, may well have been A. arborea judging from the portrait of it given by Loudon. But it is doubtful whether it has ever been much cultivated in this country. Plants seen under the label do not agree at all well with this species.
A. laevis Wieg. A. canadensis auct., in part, not (L.) Med. A. arborea subsp. laevis (Wieg.) S. Mackay ex Landry – A large shrub or small tree, glabrous in all its parts or almost so. Leaves shaped very much as in A. arborea, unfolding at flowering time and then tinted with purple or coppery brown. Flowers in racemes, the lowermost pedicels elongating in the fruiting stage. Petals somewhat longer than in A. arborea, to about [3/4] in. long, oblong. Sepals lanceolate to oblong, soon reflexing. Fruits dark purple, juicy and sweet. Native of North America from Newfoundland to Georgia, west to Illinois and Iowa.
This species is part of A. canadensis as once understood, and was first separated from this confused complex in 1912. In the wild it hybridises readily with both A. arborea and A. canadensis, and perhaps for this reason the pure species is rare in cultivation. Two different amelanchiers distributed commercially as A. laevis have been seen, neither of which is the true species but obviously the result of hybridisation, probably with A. arborea or A. canadensis. In both the leaves are tinted at flowering time, but are conspicuously hairy beneath. A. laevis sensu Clapham, Tutin and Warburg in Flora of the British Isles, first and second editions, is A. lamarckii. See further under that species.
A. confusa Hylander – This amelanchier, described from plants naturalised in Sweden, is near to A. laevis. It is quite distinct from A. lamarckii, with which it was at one time confused.