Hedychium coronarium

Hedychium coronarium, the white garland-lily or white ginger lily, is a perennial flowering plant in the ginger family Zingiberaceae, native to the forest understorey of Asia.

Other common names include butterfly lily, fragrant garland flower, Indian garland flower, white butterfly ginger lily or white ginger.

Description
It is an upright perennial which may reach 1-3 m in height. It has long pointed leaves, with heavily scented white flowers with yellow bases. In its native environment flowering occurs between August and December.

Distribution and habitat
It is native to the Eastern Himalayas of India (Sikkim and Tripura), Bangladesh, Nepal and Bhutan, through northernmost Myanmar and Thailand, southern China (Yunnan, Sichuan, Hunan, Guangxi and Guangdong) to Taiwan in the East.

It is typically found growing in forests.

Cultivation
It is cultivated in warm temperate and subtropical regions of the world as an ornamental. In China it is cultivated for use in medicine and production of aromatic oil, due to the strong characteristic fragrance of the flowers, said to be reminiscent of jasmine.

In the UK, Hedychium coronarium has received the Royal Horticultural Society's Award of Garden Merit.

Hardiness
It is evergreen in warmer climates, but deciduous in mild winter temperate regions of North America and Europe. In the UK it is rated by the Royal Horticultural Society as hardy down to -5 C in mild or coastal areas (H3).

Cuba
Hedychium coronarium is the national flower of Cuba, where it is known as mariposa (literally "butterfly") due to its shape. Women used to adorn themselves with these fragrant flowers in Spanish colonial times; because of the intricate structure of the inflorescence, women hid and carried secret messages important to the independence cause under it. The plant has become naturalized in the cool rainy mountains in Sierra del Rosario, Pinar del Rio Province in the west, the Escambray Mountains in the center of the island, and in the Sierra Maestra in the very east of it.

Invasive species
Beyond its native range H. coronarium may be invasive in shallow water systems, along streams and in waterlogged areas. Once established, it is difficult to control due to vegetative reproduction through the underground spread of rhizomes. It was introduced in Brazil in the era of slavery, said to have been brought to the country by African slaves who used its leaves as mattresses, and is now considered naturalised in the states of Rio de Janeiro (where it is classed as invasive), Bahia and Espirito Santo. This species was first introduced as an ornamental to Hawaii around 1888 by Chinese immigrants, and is now considered a serious invader in mesic to wet areas of Maui and Hawaii island. Additionally, it is invasive in South Africa, where it is a declared weed, and propagation of plant material is considered prohibited. It is also invasive in New Caledonia.