Whitebeam

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 (fall).

Appearance

The surface of the leaf is an unremarkable mid-green, but the underside is almost white (hence the name) transforming the appearance of the tree in strong winds, as noted by the poet Meredith: "flashing as in gusts the sudden-lighted whitebeam". It is also described as the "wind-beat whitebeam" in Gerard Manley Hopkins' poem "The Starlight Night".