Plants to 2 m tall, rhizome orange inside, elongating. Leaves in tufts, the blade lanceolate, narrowed at the base, to 50 cm long, 8 cm wide. Flower cluster terminal cylindrical in outline, 10-15 cm long, 5-7 cm wide. Fertile bracts oblong, pointed and mostly white and green but sometimes tinged reddish-purple. Flowers white and yellow. Lateral sterile stamens folded behind the stamen. Anther spurred at the base.
Widely grown in the tropics as a source of turmeric and naturalised in northern Qld.
There are many cultivated variants which make the taxonomy difficult (C. longa is treated as a species complex) but it has been suggested that many of the variants are sexually sterile triploids and pentaploids.
The native C. australasica Hook. f., Cape York Lily, (Native Turmeric) is also cultivated in tropical and subtropical areas; it has rhizomes that do not elongate, leaves rounded rather than narrowed at the base and lateral sterile stamens that do not fold behind the stamen.
Source: (2005). Zingiberaceae. In: . Horticultural Flora of South-eastern Australia. Volume 5. Flowering plants. Monocotyledons. The identification of garden and cultivated plants. University of New South Wales Press.