Hedychium gardnerianum (kahili ginger).

Abstract Native to the Eastern Himalayas, H. gardnerianum has been widely introduced as an ornamental in different regions of the world. It continues to be available as an ornamental and is therefore likely to spread further.H. gardnerianum is an ecologically versatile plant with rapid vegetative growth, the dense rhizome system of the plant prevents regeneration of other species. This very aggressive, shade-tolerant plant is able to form dense thickets on undisturbed sites in the understorey of open and closed-canopy native rain forests and managed forests, as well as in open areas (forest margins, ravines or path sides). Its high seed production and efficient dispersal by rats and birds, allows it to persist in invaded areas for a long time and establish new points of invasion. As H. gardnerianum is able to invade native forests, ecological, conservation and cultural values are threatened and it is a major threat to native biodiversity.