Densely clump-forming from a stout rootstock. Leaves up to 40cm or more in length by 4-8mm wide. Raceme usually shorter than leaves, fairly densely flowered. Each flower white, sometimes pale lilac, 1.2-2cm across, summer. Himalaya from Kumaon eastwards, at subtropical to temperate levels in forest. One of the largest flowered and showiest species but of suspect hardiness, even when collected near the upper altitudinal limit of its range.