A deciduous tree or large shrub described as 25 to 40 ft in the wild but already taller in cultivation; young shoots glabrous. Leaves obovate to oval, shortly pointed or blunt at the apex, usually tapered at the base, 31⁄2 to 6 in. long, about half as much wide, of firm leathery texture and conspicuously net-veined on both surfaces, dark lustrous green above, paler and rather glaucous beneath, glabrous except for down each side of the midrib; stalk 1⁄2 to 11⁄4 in. long. Flowers borne on the naked wood in March and April; peduncles glabrous. Tepals usually nine in number (occasionally up to twelve), 3 to 5 in. long, 1 to 2 in. wide, white faintly streaked and tinged with purple, hanging downward when the flower is fully expanded. Fruits shortly stalked, cylindrical, 4 in. long, 11⁄2 in. wide; seeds 3⁄8 in. long, orange-scarlet. Bot. Mag., t. 9678-9.
M. dawsoniana was found by Wilson in a remote part of W. Szechwan near Tatsien-lu (Kangting) in October 1908. He collected seeds again two years later, but never saw it in flower. Like M. sinensis, it appears to have reached this country from the nursery of Messrs Chenault of Orleans, in 1919 (according to Millais, these plants were grafted). It first flowered at Lanarth, Cornwall, in March 1937.
M. dawsoniana is a very beautiful magnolia and very hardy in its wood, but like all magnolias flowering in early spring its display may be ruined by frost, and it is slow to reach the flowering stage (fifteen years or more). Being of spreading habit it needs plenty of room and will be shy-flowering if planted in too shady a place. The largest plant at Caerhays, Cornwall, measure 54 × 51⁄2 ft at 3 ft (1971) and there are two at Trewithen in the same county, almost as tall but smaller in girth.
The only magnolia with which M. dawsoniana is likely to be confused is the typical form of M. sargentiana, which has similar flowers but, as seen in cultivation, is easily distinguished from M. dawsoniana by its lighter green leaves and tree-like habit.
The name M. dawsoniana commemorates Jackson Dawson, first Superintendent of the Arnold Aboretum, Mass., and Professor Sargent’s chief assistant in its foundation.