Betula utilis subsp. jacquemontii (Spach) Kitam.

Betula utilis subsp. jacquemontii has long been a favourite in the garden and arboretum. There is no bark of any tree quite like it, warmer in colour than the pure white of B. pendula, and with a remarkable texture. With its salmon-pink lenticels, the bark becomes tighter on older trunks. The young leaves shine brilliantly, as if lacquered, appearing scarcely pleated by their few, widely-spaced lateral veins. The texture of the leaves is limp and thin, and the teeth somewhat coarse – in contrast to the less lustrous, corrugated and more leathery leaves typical of most trees of subsp. utilis, which are also frequently cordate, with revolute, much more finely-toothed margins. The transparent brown resinous glands on the twigs of subsp. jacquemontii are larger and protrude more than those on subsp. utilis, as do the lenticels, so there is a rougher feel to them. The buds are also generally more cylindrical, longer and more acute than those of subsp. utilis.

Subsp. jacquemontii extends from Kashmir through west Nepal to the area of the deep gorge of the Kali Gandaki rivers. Ashburner & Schilling (1985) looked for a sharp geographical division between subsp. jacquemontii and subsp. utilis where they meet in Nepal, supposing that the great cleft of the Kali Gandaki River in central Nepal might provide this, but they concluded that this huge valley represented no cut-off point, but merely an acceleration in rate of change. In the wild, older trees develop thick plates of bark and form gnarled trees reminiscent of Betula ermanii on the mountains of Hokkaido or north China. At lower levels they form an open forest of scattered trees, often in association with Rhododendron campanulatum, the trunks sometimes scored with black fissures and blotches (not quite in the same manner as B. pendula). In the valleys trees are likely to be raided for fodder and firewood, or stripped of bark for roofing. Most appear white-barked, but there are brown or pink barked individuals here and there, particularly at lower altitudes.

Betula jacquemontii was described as a species from specimens collected by Victor Jacquemont in Kashmir. Before he left France to escape from a sad love affair, Jacquemont was asked to collect for the Jardin des Plantes, in any country of his choice. He chose India and in 1828, visited Royle in Saharanpur, before going to Simla and then up the Sutlej valley into Tibet. He spent 1831 in Kashmir at the invitation of the Maharajah, where he collected many new species, but died of cholera in Bombay in 1832 before he could get home; his collections were returned to Paris. His birch is labelled ‘Emodo’, from the classical name for the Himalaya.

In the ornamental landscape the tree is indispensable. To some tastes the white may perhaps seem too stark, but on a dull and drizzly winter’s day the effect can be nothing short of astonishing. Some owners – particularly those with standard trees with expanses of clear stem – have been known to sponge and polish the trunk to maintain the dazzling effect, rather in the same way as a prized classic car. Many seedlings of wild origin from Uttar Pradesh, Himachal Pradesh and Kashmir have been introduced in recent years; those from the east of the range usually perform better in cultivation. Several named clones are now well known.