Whitebeam

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Whitebeam
Sorbus aria.jpg
Common Whitebeam flowers
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Rosids
Order: Rosales
Family: Rosaceae
Genus: Sorbus
Subgenus: Sorbus subg. Aria
Pers.

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).[1]

Appearance[edit]

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".[2] It is also described as the "wind-beat whitebeam" in Gerard Manley Hopkins' poem "The Starlight Night".[3]

Ecology[edit]

The berries are a favourite of birds, though less palatable (drier, less juicy) than rowan berries. Whitebeams are sometimes used as larval food plants by Lepidoptera species including Short-cloaked Moth.

Uses[edit]

This tree is grown in parks and large gardens. The cultivars S. aria 'Lutescens'[4] and S. aria 'Majestica'[5] have gained the Royal Horticultural Society's Award of Garden Merit.

The tough, hard wood is a deep orange when wet, and pale yellow after drying. It suited for woodturning, furniture, tool handles, and cogs before the use of iron.

Part of a whitebeam branch

Classification[edit]

  • section Aria - Sorbus aria and its close relatives
  • section Alnifoliae - a group of Asian species
  • section Thibeticae - a group of species from the Himalayas and southern China
  • Sorbus intermedia group (nothosubgenus Soraria) - taxa of hybrid origin involving sections Aria and Sorbus
  • Sorbus latifolia group (nothosubgenus Tormaria) - taxa of hybrid origin involving sections Aria and Torminaria

Selected species[edit]

Sorbus subgenus Aria

Plus many other species

References[edit]

  1. ^ RHS A-Z encyclopedia of garden plants. United Kingdom: Dorling Kindersley. 2008. p. 1136. ISBN 1405332964. 
  2. ^ Meredith, G. (1851). Love in the valley. Line 207. Poems
  3. ^ Hopkins, Gerard Manley (1918). The starlight night. Line 6.
  4. ^ "RHS Plant Selector - Sorbus aria 'Lutescens'". Retrieved 4 June 2013. 
  5. ^ "RHS Plant Selector - Sorbus aria 'Majestica'". Retrieved 4 June 2013.