Chinese red birch
There are somewhere between 35 and 60 Betula species globally. They are well-known with many often seen in cultivation, grown for their ornamental qualities in both bark and foliage. Among these, Betula albosinensis is certainly among the best. Particularly recognizable for its distinctive pinkish to red bark which peels off in thin sheets, it is a tree that captures the attention of those who encounter it. The common name of Chinese red birch denotes its rich coloured bark, so the specific epithet albosinensis, suggestive of a white-barked tree, is somewhat misleading. The ovate leaves are similar to those of a number of other birches.
Betula albosinensis was described as a species in 1899 from material collected by French missionary Père Farges in Sichuan, China; like many of the plants that were first recorded by Farges, it was introduced by the great Gloucestershire-born plant hunter Ernest Wilson. Wilson collected it on a number of occasions, the first from Hubei, China, while he was collecting on behalf of the Veitch nursery. Though this first introduction may no longer be found in gardens, plants derived from some of his later collections of Chinese red birch remain in cultivation today. These include the cultivars 'Bowling Green' and 'Chinese Garden', both selected from trees grown from the same collection - WILS 4106 from Sichuan.
The Chinese red birch grows wild in west China in Hubei, Shaanxi, Gansu and Sichuan and it was from the westernmost point of this range that the variety septentrionalis was introduced. Another Wilson introduction, this time in 1908 while collecting for the Arnold Arboretum in Boston, USA, the bark is not always as attractive as plants grown as typical Betula albosinensis.
Numerous introductions have been made in recent times and these have served to increase the understanding of relationships within and among birch species. The classification of Betula is somewhat contentious and cultivated trees from various wild origins have included many intermediates between Betula albosinensis and Betula utilis. For this reason some authors have seen fit to reduce Betula albosinensis to the rank of subspecies of under Betula utilis, though for others it has been retained at specific level. However, modern treatments appear in agreement that variety septentrionalis is synonymous with Betula utilis, in the strictest sense.
Regardless of the taxonomic debate that surrounds it, the tree known to most as Betula albosinensis is more than worth its place in the garden.
Ashburner A and McAllister HA 2013. The genus Betula: a taxonomic revision of the genus. Kew Publishing.
Li P and Skortsov AK 1999. Betulaceae. In Wu Z-Y and Raven PH (eds) Flora of China: Cycadaceae through Fagaceae. Vol. 4. Beijing/St. Louis: Science Press/Missouri Botanical Garden Press, pp. 286-313.
Sargent CS 1916. Plantae Wilsonianae. Vol.2 Dioscorides Press.