Sheph. ex Ker Gawl.
Description
Hedychium gardnerianum, the Kahili ginger, is native to the eastern Himalaya of India, Nepal and Bhutan but has been very widely introduced and naturalised worldwide; GBIF records over 20,000 occurrences, the great majority from naturalised populations in Hawaii, New Zealand, the Azores, South Africa and Australia far outside its native range. In its homeland it grows in moist subtropical and lower temperate forest, on shaded banks, ravines and clearings. The images from Tserang in Bhutan at about 1100 m in September and above Yoksam in Sikkim show it flowering in late summer in its native warm, humid foothill forest belt.
It is a robust, clump-forming perennial herb arising from a stout, fleshy, branching rhizome and reaching two metres or more, with erect, leafy pseudostems formed by overlapping leaf sheaths. The leaves are large, oblong-lanceolate, glabrous above and shortly pubescent beneath, with a sheathing base and prominent midrib. The inflorescence is a dense, showy terminal cylindrical spike of many bracteate flowers; each is fragrant and lemon-yellow with a long-exserted bright red filament bearing the anther, the floral tube slender and the lip and lateral staminodes petaloid. The fruit is a fleshy capsule splitting to reveal numerous seeds enclosed in a bright orange-red aril.
Within Hedychium this species is notable for its conspicuous red stamens and is among the most ornamental gingers. The same vigour, rhizomatous spread and bird-dispersed arillate seeds make it a serious invasive in island and oceanic-climate floras, where it forms dense monocultures that suppress native regeneration, and it is listed among the world's worst invasive plants. Conservation concern thus relates not to its survival but to its impact where introduced.
Author: Sheph. ex Ker Gawl. · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China (Zingiberaceae), Branney Hardy Gingers including Hedychium, Roscoea and Zingiber