A deciduous tree 30 to 80 ft high, with a trunk 6 to 9 ft in girth, clothed with grey, rough bark, scaly on young trees; young shoots glabrous, purplish the second year. Leaves opposite, oval or ovate, mostly tapered to the base, pointed, rather fleshy in texture; variable in size, the larger ones up to 8 or 9 in. long and 4 in. wide, dark dull green and glabrous above, pale and with down on the midrib and veins beneath; chief veins in five to eight pairs; leaf-stalk reddish, 1⁄2 to 2 in. long. Flowers in terminal, rounded or pyramidal panicles as much as 10 in. wide and 6 or 8 in. high, borne on leafy shoots. Corolla white, 1 in. wide and long, funnel-shaped at the base, opening at the top into five spreading rounded lobes, downy on both surfaces, especially inside. Calyx small, urn-shaped, 1⁄4 in. long, with five rounded ciliate lobes; on a certain proportion of the flowers one lobe of the calyx becomes extraordinarily enlarged and develops into a large, white, stalked, more or less oval ‘bract’, the largest as much as 2 in. long by 11⁄2 in. wide. Stamens five, about the length of the corolla tube. Fruit a spindle-shaped capsule 1 to 11⁄2 in. long, 1⁄3 to 5⁄8 in. wide, ribbed. Seeds winged.
Native of central and south-western China; introduced by Wilson in 1907. He found it about Ichang up to 4,000 ft altitude and describes it as ‘one of the most strikingly beautiful trees of Chinese forests’. It has been grown outside at Kew since 1913 and has never suffered from winter cold and only a few times from spring frosts. Wilson was rather surprised at its hardiness. The most remarkable feature of the inflorescence is the extraordinary development of an occasional calyx-lobe, which very much resembles what is seen in Schizopbragma. The largest plant at Kew is 36 ft high and perfectly healthy but, like the others in Britain, has never flowered (1971). The tallest specimens known grow at Caerhays Castle, Cornwall; they measure 53 × 3 ft and 48 × 3 ft (1966). Judging by dried specimens the combination of flowers and large white ‘bracts’ should be very beautiful. In China they open in June and July on leafy shoots of the current year. It succeeds in open loamy soil and can be increased by cuttings of moderately ripened wood taken in August. Forrest introduced a slightly differing form of this from Yunnan, which does not grow so well in Sussex as the Wilson introduction, but has attained a height of 37 ft at Trewithen in Cornwall.
E. henryi flowered, probably for the first time in Europe, in 1971, at the Villa Taranto, Pallanza, on Lake Maggiore (Journ. R.H.S., Vol. 96 (1971), pp. 496-497 and fig. 220).