A tree growing to 70 ft high in cultivation, but the tallest in Britain are 40-50 ft high; bark smooth, grey and beech-like on mature trees; twigs slender, grey-brown, with numerous lenticels; buds copper-brown, slender, glabrous, to 1⁄4 in. or slightly more long. Leaves of thin texture, 11⁄2 to 4 in. long, 3⁄4 to 11⁄2 in. wide, the apex pointed, the base rounded, the margins double-toothed and sometimes slightly lobulate in the upper part, lateral veins parallel, in six to ten, rarely to twelve pairs, silky hairy beneath when young, becoming glabrous later; petiole 1⁄2 to 3⁄4 in. long. Flowers pure white, 3⁄8 to 1⁄2 in. wide, produced in late spring in dense corymbs 2 to 3 in. across; receptacle and pedicels glabrous or slightly silky; petals rounded; anthers cream-coloured; styles two to four. Fruits bright red or sometimes deep pink, dotted with dark lenticels, roundish or obovoid, 3⁄8 to 5⁄8 in. long, ripening in late September or October; calyx deciduous. Bot. Mag., t. 7773.
Native of Japan, Korea, and of northern and central China, as far south as Anhwei, Shantung and Kiangsi; put into commerce by the German nurseryman Späth in 1892, but perhaps cultivated earlier. It is a member of the section Micromeles, and perhaps its finest representative in gardens; indeed few other simple-leaved species surpass it as an ornamental. ‘This species can fairly easily be identified by its slim, crowded buds and twigs, and many slender lateral branches which grow along the boughs often to within a foot of the main trunk. The foliage, which is very dense in consequence, is composed of thin leaves borne in crisp-looking, overlapping clusters reminiscent of those of the native Beech or Hornbeam. In its full summer foliage this is one of the most massive in appearance of all Sorbus but the tracery of its branches in winter is noticeably delicate … . This species does not bloom conspicuously every year, but at its best … the clusters are packed 2-21⁄2 in. apart and the blossom lasts for a fortnight. With most Sorbus species the clusters are more widely spaced and much shorter lived.’ (Fox MS).
In October the chief beauty of this species is its autumn colour of apricot-pink or orange-scarlet; the fruits are usually few in each cluster and in many gardens are soon taken by birds.
S. alnifolia is an uncommon tree in Britain, despite its merits. A tree planted by Dr Fox in the Winkworth Arboretum, Godalming, in 1938 measures 40 × 33⁄4 ft at 3 ft (1975). A slightly older tree at Borde Hill in Sussex is 50 × 4 ft (1975). At the Arnold Arboretum, Boston, USA, Dr Fox saw a tree planted towards the end of the 19th century which was 70 ft high and 45 ft in spread (1955).
var. submollis Rehd. – This not very distinct variety was described as having the leaves densely downy beneath. Dr Fox records that even on a single tree there is variation from year to year in the density of hairs on the leaf-undersides. For S. zahlbruckneri Hort. (not Schneid.), sometimes placed under this variety, see Wilson 628 below.
S. alnifolia is also represented in cultivation by plants raised from seeds sent by Wilson from Hupeh, China, in 1901 (W. 628). This introduction was at first identified as S. zahlbruckneri and it was under this name that it received an Award of Merit when exhibited by Kew in 1924. Botanically, Wilson’s form differs from the original introduction in the slightly larger leaves, and the larger, cherry-like fruits. But there is the further difference that all the recorded plants have a fastigiate habit. It is probable that they all belong to a single clone, named ‘Skyline’ by Messrs Hillier.
It is possible that S. alnifolia is also cultivated in this country from seeds collected by Wilson in Korea.