Campbell's magnolia
Campbell's magnolia is a remarkable, deciduous, Himalayan member of the genus Magnolia, first found by the English surgeon-naturalist William Griffith in the forests of central Bhutan in the early nineteenth century. Griffith collected some poor herbarium specimens which were 'lost' for years following his untimely death. The beauty of Magnolia campbellii only became obvious in Britain when Joseph Hooker, the future Director of the Royal Botanic Garden Kew, came across the tree as he investigated the forests of Sikkim (India) during his explorations of the Himalayas in the late-1840s. In 1855, Hooker and his colleague Thomas Thomson formally named the plant in honour of Archibald Campbell, the British East India Company official who had facilitated Hooker's entry into Sikkim.
Magnolia campbellii attracts attention because of the huge, bucket-shaped flowers which may be up to 25 cm in diameter, and vary from white to dark pink in colour. In cultivation in Britain, the flowers open in late winter and early spring, before the leaves emerge, covering the branches. In autumn, red, fleshy-coated seeds dangle by threads from the split, mature fruits.
The native habitat of Magnolia campbellii is the mid-altitude (2,500-3,000 m) temperate forest that ranges from eastern Nepal, through Sikkim and Assam, to southwestern China and northern Myanmar. When Hooker arrived in the Himalayas the species was common but he was concerned about its future: 'in every respect ... the noblest species of the genus ... before the destruction of the grand forests that clothed the higher elevations of the outer ranges of the Sikkim Himalaya, by far the most notable tree of the district [Sikkim], and I have seen the flanks of a mountain rose-coloured in spring from its abundance and its habit of flowering before the development of the leaves'.
In cultivation, numerous colour variants have been recognised as distinct cultivars, whilst two doubtfully distinct varieties have been recognised in the native range. Variety campbellii is found in the western part of the range; the hardier variety mollicomata occupies the eastern part of the range. The prolific collector of Chinese plants, George Forrest, introduced var. mollicomata into British cultivation in 1924, whilst var. campbellii had been successfully introduced as early as 1865. Hooker was concerned Magnolia campbellii would have to be protected in a glasshouse against the British climate. However, it grows well in the milder parts of Britain, although decades may elapse before it reaches flowering size.
Further reading
Hooker JD 1885. Magnolia Campbellii. Curtis's Botanical Magazine, t.6793.
Hunt D 1998. Magnolias and their allies. International Dendrology Society & Magnolia Society.
Johnstone GH 1955. Asiatic magnolias in cultivation. The Royal Horticultural Society.
Stephen Harris