A tall shrub with erect stems, spreading by means of sucker growths from the base; said to be sometimes a small tree to 25 ft high. Leaves very woolly when quite young, ultimately becoming glabrous; firm and rather leathery when mature, 11⁄2 to 21⁄2 in. long, 1⁄2 to 11⁄4 in. wide; elliptic to oblong, more rarely widest in the lower half, rounded (rarely cordate) at the base, finely and evenly toothed, though sometimes entire near the base. Racemes erect, compact, and remaining so in fruit, covered at first with a thick, loose floss, 2 or 3 in. long, carrying numerous white flowers, the petals of which are more distinctly and uniformly obovate than in A. arborea or laevis and somewhat shorter, being at the most 2⁄5 in. long. Fruiting racemes with the lower pedicels 2⁄5 to 4⁄5 in. long. Fruit black and juicy, with the sepals erect or ascending. Bot. Mag., t. 7619.
Native of eastern N. America, usually found in bogs and swamps, and of alder-like habit. It is allied to A. arborea and laevis but differs in the more obovate petals, the erect, more compact racemes, and the erect or ascending sepals on the fruit. The habit, too, is more fastigiate. As a shrubby amelanchier it is useful in gardens, forming in time a dense thicket. Easily increased by division in spring.
This species is better known as A. oblongifolia; for the A. canadensis of previous editions, see A. arborea, but some plants grown in gardens as “A. canadensis” may be A. laevis.
From the Supplement (Vol. V)
A shrub to about 30 ft high in the wild, usually forming a clump of erect stems. Leaves oblong, oblong-elliptic or oblong-obovate, rounded to subacute or short-acuminate at the apex, rounded at the base, up to about 21⁄2 in. long and 11⁄8 in. wide, finely toothed throughout, densely white-hairy on both sides when unfolding, later almost glabrous. Flowers white, in racemes 1 to 21⁄2 in. long, the rachis, pedicels and calyx-tube hairy at first, as is the inner surface of the sepals, becoming glabrous. Petals oblong spathulate to narrowly lanceolate, about 3⁄8 in. long. Fruits juicy and sweet, blackish purple, roundish, with upright sepals.
Native of eastern North America in swamps and open woodland, from south-west Quebec to Georgia. Owing to the confusion between the true A. canadensis and other species, the date of introduction is uncertain, and indeed it has never been common in gardens, where 'A. canadensis' has usually been A. lamarckii (q.v.).
Until early this century the name A. canadensis was used in a wide sense, both by American botanists and in gardens. When Wiegand set out to establish the precise identity of the amelanchier originally named Mespilus canadensis by Linnaeus, he sent a set of specimens to an American botanist then in London, to be compared with the original specimen in the Linnean Herbarium, collected by Kalm. Unfortunately, the set did not include the true A. canadensis and the one that matched the type specimen best was of the species now known as A. arborea. Wiegand consequently concluded that A. arborea was the true A. canadensis, and in his monograph on the eastern North American amelanchiers (1912) he took up the name A. oblongifolia Roem. for what later proved to be the true A. canadensis. The confusion was not cleared up until Dr Fernald examined the type-specimen personally and published his conclusions in 1945. An unfortunate consequence of this confusion is that in the still current second edition of Rehder's Manual (1940, reprinted 1947) his A. canadensis is A. arborea and the true A. canadensis appears as A. oblongifolia. But, as already remarked, the A. canadensis of gardens was very often A. lamarckii. As for the name A. botryapium (L.f.) Borkh., this is based on the Pyrus botryapium of the younger Linnaeus, which is essentially simply an illegitimate renaming of his father's Mespilus canadensis. However, as Schroeder points out, the amelanchier actually described under Pyrus botryapium is very likely A. lamarckii, and certainly the name A. botryapium was applied to that species by later European botanists.