Vascular – Exotic
Herbs - Monocots
Terrestrial. Coastal and lowland habitats. Scrub, forest margins and clearings, roadsides and wastelands.
Non-woody perennial to 2.5 m tall, ginger-scented. Rhizomes massive, taro-like, close to ground surface, long, shallow rooted, much-branched, growing over each other forming deep beds. Rhizome segments 4 x 10 cm, each producing an aerial stem usually annually. Stems to 2.5 m, erect, soft, unbranched, thickening to short pinkish collar at base. Leaves alternate, 50 x 10 cm, shiny, pointing upwards. Flowerhead 15 x 10 cm with flowers overlapping in cone-like clusters, cream-coloured, May-Jun. No fruit produced.
Hedychium gardnerianum (wild ginger) has an open inflorescence, but is difficult to distinguish on vegetative parts alone. H. gardnerianum has shortly petiolate leaves with a small ligule to 1.5 cm. H. flavescens has sessile leaves and a ligule 3.5-5cm long. There are other Hedychium species cultivated, and sparingly naturalised. In particular H. coronarium (white ginger) is very similar but has white rather than cream flowers. Other similar species are Canna sp. and culinary Ginger (Zingiber sp.)
March, April, May, June, July
Perennial. The hermaphrodite flowers are sterile (Landcare Research 4/1993; Timmins & MacKenzie 1995). Reproduces vegetatively from short, stout rhizomes. Fruit not seen in New Zealand. Rhizomes spread slowly outwards. New infestations caused by flooding, soil movement, dumped vegetation, contaminated machinery.
Reason for introduction
Tolerant of poor drainage and semi-shade and slightly tolerant of drought. Physical damage to rhizome causes multiplication. Requires medium to high soil fertility.
flavescens: Pale yellow
National Pest Plant Accord species
This plant is listed in the 2020 National Pest Plant Accord. The National Pest Plant Accord (NPPA) is an agreement to prevent the sale and/or distribution of specified pest plants where either formal or casual horticultural trade is the most significant way of spreading the plant in New Zealand. For up to date information and an electronic copy of the 2020 Pest Plant Accord manual (including plant information and images) visit the MPI website.