A deciduous shrub 4 to 6 ft high; young shoots sparsely scurfy; afterwards glabrous, bright brown, peeling. Leaves narrowly oval-lanceolate, rounded or tapered at the base, slender-pointed, finely toothed, 11⁄2 to 5 in. long, 1⁄2 to 11⁄4 in. wide, upper surface dull greyish green, sprinkled with pale, flat, usually five- or six-rayed, stellate hairs, under-surface greyish white, covered with a close felt-like layer of eight- to twelve-rayed stellate hairs, the midrib and chief veins furnished on each side with few to many white simple hairs. Flowers in corymbose panicles, 2 to 3 in. long and wide, produced in June at the end of short two- to six-leaved twigs; each flower is about 1 in. across, pale purplish rose, paling at the margins of the petals. The wings of the inner stamens are deeply bilobed at the top, the anthers set in the notch; calyx-lobes lincar-oblong, persistent, covered like the calyx-tube and flower-stalks with pale starry scurf. Fruit 1⁄4 in. across. Bot. Mag., t. 8493.
Native of W. China; introduced by Wilson in 1905. This is one of the finest of the Chinese deutzias, both in size of flower and beauty of tint. It is closely allied to D. discolor, but is distinguished by the longer, narrower leaves, more distinctly veined beneath, and especially, by the simple hairs along the midrib – absent in discolor-, the wings of the inner stamens are deeply bilobed in discolor, but the lobes do not reach up to or above the anther as in longifolia.
var. farreri Airy Shaw – Flowers white, 1 in. wide, produced in early June in cymose clusters 2 to 3 in. long and wide. Bot. Mag., t. 9532. A native of Kansu, China; introduced by Farrer during his journey of 1914-15. He described it as a noble shrub whitening, when in flower, the coppiced slopes on which it grows ‘with a surf of snow’. A plant from the original seed is 7 ft high at Highdown, near Worthing, where it gives a beautiful display.
This deutzia was at first considered to be D. albida Batal., discovered by the Russian traveller Potanin in 1885, but in the text to the plate in the Botanical Magazine, Airy Shaw pointed out that it does not agree well with that species and is better placed under D. longifolia from which, indeed, it differs little save in the colour of the flowers. The true D. albida, which is probably not in cultivation, is also closely allied to D. longifolia.
cv. ‘Veitchii’. – A superior form with larger flowers, coloured deep lilac-pink.
D. longifolia is one parent of the important hybrid group D. × hybrida (q.v.).