Trees & shrubs – Whitebeam / Common whitebeam – Sorbus aria
The whitebeams are members of the Rosaceae family, comprising subgenus Aria of genus Sorbus, and hybrids involving species of this subgenus and members of subgenera Sorbus, Torminaria and Chamaemespilus. They are deciduous trees with simple or lobed leaves, arranged alternately. They are related to the rowans (Sorbus subgenus Sorbus), and many of the endemic restricted-range apomictic microspecies of whitebeam in Europe are thought to derive from hybrids between S. aria and the European rowan S. aucuparia; some are also thought to be hybrids with the wild service tree S. torminalis, notably the service tree of Fontainebleau Sorbus latifolia in French woodlands.
The best known species is the common whitebeam Sorbus aria, a columnar tree which grows to 25 m (82 ft) tall by 10 m (33 ft) broad, with clusters of white flowers in spring followed by speckled red berries in autumn.
Wayside and Woodland Trees
A POCKET GUIDE TO THE BRITISH SYLVA
EDWARD STEP, F.L.S.
Owing to its very local occurrence, the White Beam, though widely distributed, is one of the less known of our trees and shrubs. It comes into both these categories according to the situation of its growth, for whilst in exposed mountainous localities a specimen of mature age may be no more than four or five feet high, and of bush-like growth, under the lee of a wood, and on a calcareous soil, it will be an erect and graceful tree of pyramidal form, whose apex is forty feet from the ground. In its early years growth is tolerably rapid, but at the age of ten it slackens pace, and after it has attained its majority its progress is very slow. Its wood is fine-grained, very hard, white, but inclining to yellow. The bark is smooth, and little subject to the cracks and fissures that mark the Apple-bark. The branches, except a few of the lowest, all have an upward tendency.
The leaves vary considerably in the several forms or sub-species, but in the typical form they are a broad oval, with the edges coarsely toothed or cut into lobes, the upper side smooth, and the lower side clothed with white cottony down, the almost straight nerves strongly marked. The white flowers, which appear in May or June, are only half an inch across, and gathered into loose clusters. They are succeeded by nearly round scarlet fruits, half an inch in diameter, known in Lancashire and Westmoreland as Chess-apples. The tree is also known in the same districts as Sea Owler, the latter word, according to Prior, being a corruption of Aller or Alder, probably from the resemblance of the plaited leaves to those of Alnus glutinosa. These Chess-apples are very sharp and rough to the taste, but when kept like Medlars, till they “blet” or begin to decay, are far from unpleasant. Birds and squirrels eagerly seek for them on the tree, and those that fall are as welcome to hedgehogs and other mammals. This form is only found from the Midlands to the South of England as far west as Devon, and in Ireland.
Gorgeous Whitebeam (Sorbus aria) leaves appearing, showing what it's named for… pic.twitter.com/MEyXzqgYFG
— The Street Tree (@TheStreetTree) May 4, 2016
The sub-species latifolia (Pyrus rotundifolia of some botanists) has broader leaves, varying from oval-oblong to almost round, divided into wedge-shaped lobes, the cottony down beneath being grey rather than white, and the nerves less prominent on the underside. This form is found in Cornwall.
The sub-species scandica (also known as Pyrus intermedia) has the leaves less tough, more deeply divided into rounded or oblong lobes, and the grey cotton beneath of a looser character. This form is found in Scotland.
It should be noted that this species must not be called the White Beam-tree, for the word beam is the Saxon equivalent for tree. Other names for it include Hen-apple, Cumberland Hawthorn, Hoar Withy, Quick Beam, and Whipcrop
Webster listed the Whitebeam as follows.
PYRUS ARIA.—White Beam. Europe (Britain). A shrub or small-growing tree, with lobed leaves, covered thickly on the under sides with a close, flocculent down. The flowers are small and white, and produced in loose corymbs. It is a handsome small tree, especially when the leaves are ruffled by the wind and the under sides revealed to view. The red or scarlet fruit is showy and beautiful.
— The Street Tree (@TheStreetTree) November 23, 2015