Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide


Hedychium flavescens
(wild ginger)



Hedychium flavescens (wild ginger)


  • Last modified
  • 22 November 2018
  • Datasheet Type(s)
  • Invasive Species
  • Preferred Scientific Name
  • Hedychium flavescens
  • Preferred Common Name
  • wild ginger
  • Taxonomic Tree
  • Domain: Eukaryota
  •   Kingdom: Plantae
  •     Phylum: Spermatophyta
  •       Subphylum: Angiospermae
  •         Class: Monocotyledonae
  • Summary of Invasiveness
  • A native of the Himalayas, H. flavescens has been introduced to many locations around the world as an ornamental and subsequently escaped cultivation to become a weed of significant economic importance in count...

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Hedychium flavescens (wild ginger); flowers. Hana Hwy, Maui, Hawaii, USA. Novembe 2009.
CaptionHedychium flavescens (wild ginger); flowers. Hana Hwy, Maui, Hawaii, USA. Novembe 2009.
Copyright©Forest & Kim Starr-2012 - CC BY 4.0
Hedychium flavescens (wild ginger); flowers. Hana Hwy, Maui, Hawaii, USA. Novembe 2009.
FlowersHedychium flavescens (wild ginger); flowers. Hana Hwy, Maui, Hawaii, USA. Novembe 2009.©Forest & Kim Starr-2012 - CC BY 4.0
Hedychium flavescens (wild ginger); flowers and leaves. Nahiku, Maui, Hawaii, USA. June 2009.
CaptionHedychium flavescens (wild ginger); flowers and leaves. Nahiku, Maui, Hawaii, USA. June 2009.
Copyright©Forest & Kim Starr-2009 - CC BY 4.0
Hedychium flavescens (wild ginger); flowers and leaves. Nahiku, Maui, Hawaii, USA. June 2009.
HabitHedychium flavescens (wild ginger); flowers and leaves. Nahiku, Maui, Hawaii, USA. June 2009.©Forest & Kim Starr-2009 - CC BY 4.0
Hedychium flavescens (wild ginger); infestation and habit.Waikamoi Stream, Waikamoi, Maui, Hawaii, USA. September 2018.
CaptionHedychium flavescens (wild ginger); infestation and habit.Waikamoi Stream, Waikamoi, Maui, Hawaii, USA. September 2018.
Copyright©Forest & Kim Starr-2018 - CC BY 4.0
Hedychium flavescens (wild ginger); infestation and habit.Waikamoi Stream, Waikamoi, Maui, Hawaii, USA. September 2018.
HabitHedychium flavescens (wild ginger); infestation and habit.Waikamoi Stream, Waikamoi, Maui, Hawaii, USA. September 2018.©Forest & Kim Starr-2018 - CC BY 4.0


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Preferred Scientific Name

  • Hedychium flavescens N. Carey ex Roscoe 1824

Preferred Common Name

  • wild ginger

Other Scientific Names

  • Hedychium coronarium var. flavescens J. König (Roscoe) H. Perrier
  • Hedychium emeiense Z. Y. Zhu
  • Hedychium flavum auct. non Roxb
  • Hedychium panzhuum Z. Y. Zhu

International Common Names

  • English: cream garland lily; cream ginger; cream ginger lily; yellow ginger; yellow ginger lily
  • French: gingembre jaune; gingembre-douleur; hédychie jaunâtre; longose; longose à fleurs jaunes; longose jaune vanille; longoze

Local Common Names

  • Australia: white ginger
  • China: e mei jiang hua
  • Cook Islands: kaopui rengarenga; kopi rengarenga; re‘a; re‘a rengarenga
  • French Polynesia: opuhi rea rea
  • Niue: kamapui fiti tea; keuila
  • Réunion: hédychie jaunâtre
  • Samoa: teuila
  • USA/Hawaii: ‘awapuhi melemele

Summary of Invasiveness

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A native of the Himalayas, H. flavescens has been introduced to many locations around the world as an ornamental and subsequently escaped cultivation to become a weed of significant economic importance in countries with favourable moist and warm climates. It threatens native forests in New Zealand, in La Réunion it outcompetes native plants and forms dense stands in wet areas such as ravine sides, roadsides, native forest margins and disturbed forests, and in Hawaii it tends to be confined to forest edges but also impacts negatively on the ecosystem. Its spread and dispersal is facilitated by vegetative regeneration of its dense rhizomes, which allows it to cover large areas of land and prevent the re-growth and establishment of native species, endangering rare and specialized plant communities. It is similar in its ecology and impacts to other invasive Hedychium spp., e.g. Hedychium coronarium and Hedychium gardnerianum.

Taxonomic Tree

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  • Domain: Eukaryota
  •     Kingdom: Plantae
  •         Phylum: Spermatophyta
  •             Subphylum: Angiospermae
  •                 Class: Monocotyledonae
  •                     Order: Zingiberales
  •                         Family: Zingiberaceae
  •                             Genus: Hedychium
  •                                 Species: Hedychium flavescens

Notes on Taxonomy and Nomenclature

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The pantropical Zingiberaceae is the largest family in the order Zingiberales with 53 genera and over 1200 species. The taxonomy of the horticulturally important genus Hedychium has been controversial since the mid-1800s, and it is currently estimated that there are 65 valid species (Wood et al., 2000). A new classification of the Zingiberaceae by Kress et al. (2002) based on molecular characterisation places the genera Hedychium within the subfamily Zingiberoidea Haask., tribe Zingiberae.

H. flavescens was known in New Zealand as H. flavum and later referred to by Orchard (1973) as H. coronarium var. subditum, largely based on the work and modifications of Turrill (1914) and Naik and Panigrahi (1961). This taxa was subsequently reduced to a synonym of H. flavescens Carey ex Roscoe on the basis of intermediate specimens found in Madagascar (Lourteig, 1972). Much confusion surrounds the nomenclature of the H. coronarium complex, due primarily to the paucity of wild collected herbarium specimens to document interspecific variations in populations, and due to the widespread cultivation, selection and hybridisation which this has entrained. So whilst H. flavescens is often considered a synonym of H.flavum, these are thought to represent two distinct species. To add to the confusion, it often seems that in horticulture these two plant names are used interchangeably due to the name similarity.

The genus Hedychium are known as gingers, and there are several common names in English for H. flavescens, of which wild ginger and yellow ginger appear to be the most widespread.


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H. flavescens is a coarse perennial herb with thick fleshy rhizomes and erect, leafy pseudostems of 1-3 m in height. The leaves are sessile and have slightly pubescent sheaths. The ligule is 3-5 cm long and membranous. Leaf blades are elliptic-lanceolate or lanceolate, 20-50 cm long and 4-10 cm wide and abaxially (beneath) pubescent with attenuate base, membranous margins and a caudate-acuminate apex. Inflorescences are oblong spikes, 15-20 cm long and 3-6 cm wide; bracts are imbricate, oblong to ovate, 3-4.5 cm long and 2-4 cm wide, concave, 4- or 5-flowered. The bracteoles are tubular and membranous. Flowers are creamy-white to pale yellow or yellow-white in a cone like inflorescence, fragrant with yellow stamens. The calyx is 3.5-4 cm long, pubescent, approximately half the length of the corolla tube and almost as long as the bract. It is split on 1 side, apical margin entire. Corolla tube is 7-8.5 cm, long and slender. The lobes are linear, 3-3.5 cm long. The lateral staminodes are wider than the corolla lobes. The labellum is erect, creamy yellow with an orange patch at base, obcordate, longer than wide, and apex is 2-lobed. Filament is white to cream, subequaling labellum. Top of anther protruding slightly beyond lip. Ovary hairy. Stigma funnelform, margin bearded. Fruits are globose capsules 1-2 cm in diameter with three valves, containing numerous seeds but not seen in much of its invasive range.

Plant Type

Top of page Broadleaved
Seed propagated
Vegetatively propagated


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Fossil records suggest that after the Tertiary, the Zingiberaceae of Europe and North America disappeared leaving those sheltered from glaciation to develop continuously in South-East Asia, which became the centre of present distribution and species diversity (Wu, 1994).

H. flavescens is native to the eastern Himalayas, including Nepal and north-eastern India (Assam, Meghalaya and Sikkim). Herbarium records from India’s Central National Herbarium also report localities as far south as Kerala and Tamil Nadu; however, H. flavescens is now widely introduced and naturalized in various tropical countries, and was probably introduced to areas neighbouring its native range. In the eastern part of its range, it is often planted around Buddhist shrines.

Distribution Table

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The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Continent/Country/RegionDistributionLast ReportedOriginFirst ReportedInvasiveReferenceNotes


ChinaPresentPresent based on regional distribution.
-SichuanPresentIntroduced Not invasive eFloras, 2008500-800 m; forests and naturalized along ditches and water courses (Mount Omei)
IndiaPresentNativeUSDA-ARS, 2008; USDA-ARS, 20081200-2000 m
-AssamPresentNative Not invasive Natural History Museum Herbarium, UKNaga Hills
-KeralaPresentIntroduced Not invasive Central National Herbarium, Botanical Survey of IndiaTrichur District 1240 m
-MeghalayaPresentNative Not invasive Natural History Museum Herbarium, UKKhasi Hills
-SikkimPresentNative Not invasive Hooker, 1897
-Tamil NaduPresentIntroducedCentral National Herbarium, Survey of IndiaNilgiri District, Karianhola, 2067 m
NepalPresentNative Not invasive USDA-ARS, 2008Dhankuta
Sri LankaPresentIntroducedBaby et al., 2007
VietnamPresentIntroducedMissouri Botanical Garden, 2008


KenyaPresentIntroduced Invasive Witt and Luke, 2017
MadagascarPresentIntroducedLourteig, 1972
MalawiPresentIntroducedWitt and Luke, 2017
RéunionPresentIntroduced1825 Invasive Baret et al., 2006
South AfricaPresentIntroducedHenderson, 2001; AGIS, 2007
ZambiaPresentIntroducedWitt and Luke, 2017Naturalized

North America

USAPresentPresent based on regional distribution.
-HawaiiPresentIntroduced Invasive Anderson and Gardner, 1999; Wagner et al., 1999; PIER, 2008Kamakou Preserve, wetter northern valleys of Kauai, Maui, Moloka’I, O’ahu, Big Island

Central America and Caribbean

Puerto RicoPresentIntroducedUSDA-NRCS, 2008


PortugalPresentPresent based on regional distribution.
-AzoresPresentIntroduced Invasive Naturalized


American SamoaPresentIntroduced Invasive PIER, 2008Tutuila Isl.
AustraliaPresentPresent based on regional distribution.
-QueenslandPresentIntroduced Invasive Queensland Department of Primary Industries and Fisheries, 2008Mt Glorious and Lamington National Park, Mt Tamborine and near Mackay, coastal, subtropical and upland tropical forests
Cook IslandsPresentIntroduced Invasive McCormack, 2007; PIER, 2008Atiu Isl., Mangaia, Rarotonga
FijiPresentIntroducedPIER, 2008Rotuma Island
French PolynesiaPresentIntroducedPIER, 2008Tahiti, Raiatea islands
GuamPresentIntroducedPIER, 2008Guam Island
Micronesia, Federated states ofPresentIntroduced Invasive PIER, 2008Pohnpei, Kosrae, Yap
New CaledoniaPresentIntroducedPIER, 2008Ile Grande Terre
New ZealandPresentIntroduced1898 Invasive PIER, 2008Coromandel Peninsula, Auckland, Bay of Plenty, Northland, Northern South Island
NiuePresentIntroduced Invasive PIER, 2008Niue Island
SamoaPresentIntroduced Invasive PIER, 2008Forest understory; Upolu Island
TongaPresentIntroduced Invasive PIER, 2008Vava’u Island

History of Introduction and Spread

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It is unknown when it was introduced from its native range to neighbouring areas such as to Emei Shan (Mount Omei) in Sichuan, China (Armstrong et al., 2004), southern India and Sri Lanka.

Hedychium spp. were extensively cultivated in Europe in the early 1800s for their exotic forms and fragrant perfume, making the wild gingers prized ornamentals in tropical glasshouses. From the UK, the cultivation of gingers spread to parts of the British Empire, with many species transported to warmer areas of the tropics and subtropics (Orchard, 1978). Under these favourable conditions, H. flavescens (along with H. gardnerianum) escaped from cultivation to become economically important weeds. 

A serious weed in New Zealand and a major threat to native forests, it was introduced there around 130 years ago (Winks et al., 2007), with Owen (1986) noting 1898 as the date of first introduction, the plant having spread rapidly since the 1970s, with H. flavescens having a narrower distribution than H. gardnerianum. It was introduced to La Réunion in the 1900s (Radjassegarane, 1999; Baret et al., 2006), and to Hawaii probably about the same time before later being spread more widely around the Pacific. It is likely to be more widespread than indicated in the distribution list.

Risk of Introduction

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Further spread is highly probable, owing to the risks of both accidental and deliberate dumping of rhizomes locally, and deliberate long-distant introduction as an ornamental, encouraged by availability from commercial nurseries by mail-order catalogues and websites.

H. flavescens is prohibited as a noxious weed in New Zealand and it is a proscribed species to be intercepted at entry points. It is subject to a Pest Plant Management Strategy in Taranaki, New Zealand and is listed on the National Pest Plant Accord. H. flavescens has been designated as a ‘Progressive control pest’ by the Tasman-Nelson Regional Pest Management Strategy. The strategy has its effect over the combined area that lies within the administrative boundaries of the Tasman District Council and Nelson City Council. The objective of the strategy is to reduce the distribution and density of H. flavescens in the Golden Bay/Kaiteriteri area during the term of the Strategy. In the Auckland region, H. gardnerianum and H. flavescens have both been designated as Surveillance, Community Initiative and Containment Pests.

The objectives of the management strategy are to prevent the spread of and, where practicable, reduce infestations of H. gardnerianum and H. flavescens over the next five years, from the Waitakere and Hunua Ranges Weed Control Zones, and Great Barrier Island; and to restrict their further spread by humans over the next 10 years. Wild gingers are a total control plant pest in the Bay of Plenty region. Occupiers of land are required to control all wild ginger plants growing on their land. It is also a classified ‘Containment pest plant’ in the Taranaki part of New Zealand, being a plant that is abundant in suitable habitats in a region or part of a region and for which the long-term goal is to prevent the spread of the plant to new areas or to neighbouring properties, with each pest plant having a management programme according to its designation. Greater Wellington has proposed moving wild ginger (H. flavescens and H. gardnerianum) to the Site Led pest category with a 10 m boundary clearance rule. Site Led pests are well established throughout the region and not cost effective to control on a region-wide scale. Therefore, management is focused on specific sites where the pests have the most serious impact, and the benefits of control are greatest.

It is a Category 1 plant in South Africa’s Declared Weeds and Alien Invader Plants List, being the strictest category. These plants may not occur on any land or inland water surface other than in a biological control reserve. Except for the purposes of establishing a biological control reserve, one may not plant, maintain, multiply or propagate such plants, import or sell or acquire propagating material of such plants except with the written exception of the executive officer.

In Australia it is a registered weed under state and territory legislation but permitted under federal legislation as determined using the Australian Quarantine and Inspection Service’s (AQIS) Import Conditions Database (ICON, 2006).

There are no regulations in La Réunion but it was ranked 21st in importance according to Macdonald et al. (1991). However, H. flavescens is a proscribed species to be intercepted at entry points to Hawaii.


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H. flavescensoccurs in agricultural areas, rainforest, moist natural forests, planted forests, riparian zones, ruderal/disturbed land, urban areas and along roads. It is a serious weed in riverbanks, natural forests and forest edges, managed forestry; a principal weed in wet areas such as ravine sides, roadsides, native forest margins and disturbed forests in La Réunion, where it is most invasive along water courses, being found across four habitats from lowland rainforest to leeward mountain rainforest (Radjassegarane, 1999; Baret et al., 2006). In Hawaii, it is commonly cultivated and naturalized in moist areas (Healy and Edgar, 1980), considered weedy but usually confined to forest edges instead of invading the understorey. In New Zealand, it threatens native forests and occurs on roadsides and stream banks (Wagner et al., 1999), also in the north of North Island along forest margins and stream-sides, with some coastal patches around human settlements on South Island. It is naturalized along ditches and water courses where introduced in Sichuan, China (Armstrong et al., 2004), and in Sri Lanka from below 2000 m and along water courses and in well irrigated areas.

As well as being a major weed in New Zealand and Hawaii where it dominates understorey vegetation in rainforests, H. flavescens is a threat to coastal, subtropical and upland tropical forests in Queensland, Australia. In and around the Pacific at least, H. flavescens appears to have a similar ecology to the related invasive species H. coronarium and H. gardenarium (PIER, 2008).

Habitat List

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Terrestrial – ManagedCultivated / agricultural land Present, no further details Natural
Managed forests, plantations and orchards Present, no further details Harmful (pest or invasive)
Disturbed areas Present, no further details Harmful (pest or invasive)
Disturbed areas Present, no further details Natural
Rail / roadsides Present, no further details Harmful (pest or invasive)
Urban / peri-urban areas Present, no further details Harmful (pest or invasive)
Terrestrial ‑ Natural / Semi-naturalNatural forests Principal habitat Harmful (pest or invasive)
Natural forests Principal habitat Natural
Riverbanks Principal habitat Harmful (pest or invasive)
Riverbanks Principal habitat Natural
Coastal areas Secondary/tolerated habitat Harmful (pest or invasive)

Hosts/Species Affected

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H. flavescens is not a weed of crops. It is an invasive species that threatens the environment, native communities and biodiversity.

Biology and Ecology

Top of page Genetics

The chromosome number is reported to be 2n=34.

Physiology and Phenology

H. flavescens, like its close relative, H. flavum, possesses large yellow inflorescences but can be distinguished from the latter by its hairier leaves and generally paler yellow flowers. The Zingiberoideae have a forced dormancy period during which all the above ground parts are shed and the plant overwinters as a thick, fleshy rhizome. Either just before or at the earliest signs of the wet season, individuals break dormancy with vegetative or reproductive shoots.

Reproductive Biology

Spread in its invasive range is mainly by vegetative growth via rhizomes; however, in Hawaii some evidence exists that H. flavescens may be naturalizing by seed, though no fertile fruits have yet been found.

Environmental Requirements

H. flavescens is a plant of the humid tropics, though being native to high altitudes, it can also tolerate cooler temperatures if in fully humid climates. It prefers areas with a mean annual rainfall of 1000-5000 mm, a mean annual temperature of 11-20ºC, and it can also tolerate frosts, though they may kill above-ground plant parts. H. flavescens requires medium to high soil fertility, and prefers to grow in open, light-filled environments which are warm and moist but will readily colonise semi and full shade under forest canopies. Altitude range in its native India is 1200-2000 m (Hooker, 1897; Mitra, 1958), 500-800 m in Sichuan, south-western China, below 2000 m Sri Lanka, and below 400 m in Hawaii but up to 2300 m where annual rainfall exceeds 1500 mm.


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Af - Tropical rainforest climate Preferred > 60mm precipitation per month
Am - Tropical monsoon climate Preferred Tropical monsoon climate ( < 60mm precipitation driest month but > (100 - [total annual precipitation(mm}/25]))
Cf - Warm temperate climate, wet all year Preferred Warm average temp. > 10°C, Cold average temp. > 0°C, wet all year

Air Temperature

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Parameter Lower limit Upper limit
Absolute minimum temperature (ºC) 0 -5
Mean annual temperature (ºC) 20 11
Mean maximum temperature of hottest month (ºC) 17 14
Mean minimum temperature of coldest month (ºC) 13 10


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ParameterLower limitUpper limitDescription
Dry season duration01number of consecutive months with <40 mm rainfall
Mean annual rainfall50001000mm; lower/upper limits

Rainfall Regime

Top of page Summer

Soil Tolerances

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Soil drainage

  • impeded
  • seasonally waterlogged

Soil texture

  • heavy
  • medium

Natural enemies

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Natural enemyTypeLife stagesSpecificityReferencesBiological control inBiological control on
Hypochniciellum ovoideum Pathogen not specific

Notes on Natural Enemies

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Due to its economic importance, the wide range of pests and diseases attacking cultivated ginger have been well researched. By contrast however, not much is known about the mycobiota and entomofauna of wild ginger species. Very few fungal pathogens had been reported on H. flavescens in its invasive range (Farr et al., 2008) although a strain of the soil-borne bacterium, Ralstonia solanacearum was isolated from Zingiber officinale (edible ginger) in Hawaii and caused no bacterial wilt in H. flavescens despite causing symptoms in H. gardnerianum and H. coronarium (Anderson and Gardner, 1999). The basidiomycete Leptosporomyces ovoideus was also recorded from H. flavescens in Hawaii (Farr et al., 2008).

Biological control options were subsequently investigated in New Zealand (Winks et al., 2007) following on from the research carried out in Hawaii. A survey of fungi, bacteria and invertebrates associated with H. flavescens (and H. gardnerianum) in New Zealand was carried out in 2006-07 for a national collective of regional councils and the Department of Conservation but no specialist agents were found. Furthermore, no isolates of R. solanacearum were found during the course of the surveys, even though it is recorded as present in New Zealand on other hosts, and it was concluded that the strain known to attack gingers was not established in New Zealand. Given the lack of specialist agents in New Zealand, recommendations were made that a classical control programme should be made, involving surveys in the native range of the wild ginger species of concern. A scoping survey to the Eastern Indian foothills of the Himalayas was carried out in 2008 by CABI scientists, sponsored by a consortium from Hawaii and New Zealand, and highlighted a large suite of damaging natural enemies associated with the Hedychium complex. Subsequent phases of the project have continued to consolidate and prioritise natural enemies for specificity studies, with the focus of the research being on H. gardnerianum, the most pernicious of the invasive complex.

A shoot borer (Conogethes puctiferalis) and a leaf roller (Udaspes folus) have been recorded from Hedychium sp. in India and several species of pathogens have been documented from Hedychium species including the basidiomycete, Lecanocybe lateralis Desjardin & E. Horak, from senescent leaves of H. flavescens (Indonesia) (Soares and Barreto, 2008) and Leptosporomyces ovoideus from H. flavescens in Hawaii (Gilbertson et al., 2002).


Means of Movement and Dispersal

Top of page Natural Dispersal (Non-Biotic)

Locally, H. flavescens spreads outwards along the ground by way of rhizomes, with new stems sprouting annually. In New Zealand, the hermaphrodite flowers are sterile (Timmins and MacKenzie, 1995) as it is in much of its invasive range, and as it does not produce seeds its spread appears to be entirely vegetative. Flooding may also aid in the spread of rhizomes.

Vector Transmission (Biotic)

Feral pigs may aid in local dispersal of rhizomes at least in Hawaii.

Accidental Introduction

Dumping of material in inappropriate places by people is the main form of spread and its subsequent aggressive growth rate, makes it an overwhelming plant wherever the rhizomes fall, regenerating from even the smallest root fragments. New infestations also caused by soil movement, dumped vegetation or contaminated machinery.

Intentional Introduction

H. flavescens, like so many gingers, is used for ornamental purposes; horticulturists sell rhizomes or plants and seeds are available for purchase on the internet. As such, further deliberate introductions of H. flavescens are highly likely.

Pathway Vectors

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Plant Trade

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Plant parts liable to carry the pest in trade/transportPest stagesBorne internallyBorne externallyVisibility of pest or symptoms
Bulbs/Tubers/Corms/Rhizomes Pest or symptoms usually visible to the naked eye
Flowers/Inflorescences/Cones/Calyx Pest or symptoms usually visible to the naked eye
Fruits (inc. pods) Pest or symptoms usually visible to the naked eye
Seedlings/Micropropagated plants Pest or symptoms usually visible to the naked eye
True seeds (inc. grain) Pest or symptoms usually visible to the naked eye

Impact Summary

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Cultural/amenity Negative
Economic/livelihood Negative
Environment (generally) Negative

Economic Impact

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There are no records of direct impact on crops, but mechanical and chemical control of H. flavescens can be costly.

Environmental Impact

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Environmental impacts are similar to that of H. gardnerianum. Its ability to form dense colonies in native forests, smothering young natives, blocking the light and preventing seedling establishment can lead to alterations of both function and structure of these native forests and in some cases total collapse. The massive branching rhizomes and horizontal underground stems produce new buds and form a dense layer up to a metre thick, which other plants cannot penetrate. It may permanently displace uncommon plants or specialised plant communities. Like H. gardnerianum, it may interfere with the successional pathways in the forests it invades by reducing densities of small seedlings and saplings in the critical regeneration phase, impacting on the future canopy composition (Williams et al., 2003). In La Réunion, strong competition for light also occurs in sites invaded by H. flavescens, which catches 85-95% of the incident light (Lavergne et al., 2003), and in such environmental conditions, regeneration of native species decreases (Lavergne et al., 2004). Wild ginger also impacts on the nutrient and hydrological regimes of an ecosystem and erosion/deposition (Williams et al., 2000).

Impact on Biodiversity

H. flavescens produces massive branching rhizomes capable of forming dense layers up to a metre thick which other plants cannot penetrate therefore it physically outcompetes and smothers native flora and native ecosystems and threatens biodiversity, much as H. gardnerianum. In addition to impact on plant biodiversity, Williams et al. (2000) also suggest there may be impacts on animal biodiversity and behaviour as a result of infestations.

Threatened Species

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Threatened SpeciesConservation StatusWhere ThreatenedMechanismReferencesNotes
Loxioides bailleui (palila)CR (IUCN red list: Critically endangered) CR (IUCN red list: Critically endangered); USA ESA listing as endangered species USA ESA listing as endangered speciesHawaiiEcosystem change / habitat alterationUS Fish and Wildlife Service, 2006
Psittirostra psittacea (Ou)CR (IUCN red list: Critically endangered) CR (IUCN red list: Critically endangered); USA ESA listing as endangered species USA ESA listing as endangered speciesHawaiiEcosystem change / habitat alterationUS Fish and Wildlife Service, 2006; US Fish and Wildlife Service, 2009

Social Impact

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Dense populations can interfere with access to amenity areas, encroaching on path sides and generally reducing amenity values, even regarding its ornamental value.

Risk and Impact Factors

Top of page Impact outcomes
  • Damaged ecosystem services
  • Ecosystem change/ habitat alteration
  • Modification of hydrology
  • Modification of nutrient regime
  • Modification of successional patterns
  • Monoculture formation
  • Negatively impacts forestry
  • Reduced amenity values
  • Reduced native biodiversity
  • Threat to/ loss of endangered species
  • Threat to/ loss of native species
  • Transportation disruption
Impact mechanisms
  • Competition - monopolizing resources
  • Competition - shading
  • Competition - smothering
  • Hybridization
  • Rapid growth
Likelihood of entry/control
  • Highly likely to be transported internationally accidentally
  • Highly likely to be transported internationally deliberately
  • Difficult/costly to control


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H. flavescens is best known as a spectacular flowering plant, introduced all over the world as an ornamental due to its beautiful and fragrant flowers. It is available via the internet from horticulturist websites. It is also used in ‘lei making’ (flower weaving) in Hawaii, and is popularly used in women’s hair in other areas.

The chemical composition of the essential oils from the rhizomes of several Hedychium spp. were investigated, including H. flavescens from southern India and the strongest activities were observed for the rhizome oil from H. flavescens, especially against Salmonella typhi, Escherichia coli, Proteus vulgaris and the fungi Candida albicans and Candida glabrata (Baby et al., 2007).

Uses List

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  • Amenity
  • Ornamental


  • Botanical garden/zoo
  • Ritual uses
  • Sociocultural value


  • Essential oils


  • Cut flower
  • Potted plant
  • Propagation material
  • Seed trade

Similarities to Other Species/Conditions

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Four Hedychium species are very common and can be distinguished by the colour of their flowers. H. coccineum has red or reddish orange flowers, and has more slender upright leaves. H. coronarium has white flowers which are sweetly fragrant. H.flavescens leaves are slightly narrower than those of H. gardnerianum and the flower head is also much smaller and a paler yellow in colour. Also, there is confusion with H. flavum, especially as in horticulture, the names are sometimes used interchangeably, though H. flavescens has wider bracts, dark in colour, and autumn flowering, whereas H. flavum has distinctively narrower bracts, medium green in colour, and flowers earlier.


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AGIS, 2007. Agricultural Geo-Referenced Information System.

Anderson RC, Gardner DE, 1999. An evaluation of the wilt-causing bacterium Ralstonia solanacearum as a potential biological control agent for the alien kahili ginger (Hedychium gardnerianum) in Hawaiian forests. Biological Control, 15(2):89-96; 27 ref

Armstrong N, Clough P, McMillan PDA, 2004. Hedychiums and others. In: Gardening on the Edge: Drawing on the Cornwall Experience UK: Alison Hodge Publishers, 155-168

Auckland Regional Council, 1999. Wild ginger: Hedychium gardnerianum, H. flavescens. Pestfacts

Baby S, Varughese G, Mathew D, Nediyaparambu Sukumaran P, 2007. Chemical Composition and Antimicrobial Activities of the Essential Oils from the Rhizomes of Four Hedychium Species from South India. Journal of Essential Oil Research

Baret S, Rouget M, Richardson DM, Lavergne C, Egoh B, Dupont J, Straberg D, 2006. Current distribution and potential extent of the most invasive alien plant species on La Réunion (Indian Ocean, Mascarene islands). Austral Ecology, 31(6):747-758

Bussaban B, Lumyong P, McKenzie EHC, Hyde KD, Lumyong S, 2002. Index of fungi described from the Zingiberaceae. Mycotaxon, 83:165-182

Cronk QCB, Fuller JL, 1995. Plant invaders: the threat to natural ecosystems. London, UK; Chapman & Hall Ltd, xiv + 241 pp

DAISIE, 2008. European Invasive Alien Species Gateway.

eFloras, 2008. Hedychium flavescens. Flora of China. USA: Missouri Botanical Garden Press, 372.

Environment Bay of Plenty, 2008. Wild ginger - Hedychium gardnerianum, Hedychium flavescens. Plant Pest Control Fact Sheet PP02/98. Whakatane, NZ: Environment Bay of Plenty (Env. Bop)

Farr DF, Rossman AY, Palm ME, McCray EB, 2008. Fungal Databases. Fungal Databases. . USA: Systematic Mycology and Microbiology Laboratory, USDA-ARS.

Fournet J, 2002. Illustrated flora of Spermatophyta from Guadeloupe and Martinique: Part 1. Flore illustre^acute~e des phane^acute~rogames de Guadeloupe et de Martinique. Tome^acute~ 1, 1324 pp

Gilbertson RL, Bigelow DM, Hemmes DE, Desjardin DE, 2002. Annotated check list of wood-rotting basidiomycetes of Hawai'i. Mycotaxon, 82:215-239

Harris R, Steward C, Syrett P, 1996. Wild Ginger (Hedychium spp.): Prospects for Biological Control. Lincoln, New Zealand: Landcare Research New Zealand Ltd

Healy AJ, Edgar E, 1980. Flora of New Zealand. Volume III: Adventive cyperaceous, petalous & spathaceous monocotyledons. Wellington, New Zealand: Government Printer, 220 pp

Henderson L, 2001. Alien weeds and invasive plants: a complete guide to declared weeds and invaders in South Africa. Plant Protection Research Institute, Handbook 12

Hivert J, 2003. Plantes exotiques envahissantes - Etat des méthodes de lutte mise en oeuvre par l'Office National des Forêts à La Réunion. Reunion: ONF Réunion

Hooker JD, 1897. Flora of British India. Kent, England: L. Reeve & Co. Ltd

ICON, 2006. Australian Quarantine and Inspection Service (AQIS) import conditions database.

ISSG, 2005. Global Invasive Species Database (GISD). Auckland, New Zealand: University of Auckland.

Karthikeyan S, Jain SK, Nayar MP, Sanjappa M, 1989. Botanical Survey of India. Flora of India. Series 4. Florae Indicae Enumeration: Monocotyledonae

Kress WJ, Prince LM, Williams KJ, 2002. The phylogeny and a new classification of the gingers (Zingiberaceae): evidence from molecular data. American Journal of Botany, 89(10):1682-1696

Lavergne C, Florens V, Strasberg D, 2004. Eradication of invasive alien plants has consequences on biodiversity: the case study of Hedychium gardnerianum in Reunion Island- INVABIO Programme. In: Workshop on Biodiversity Dynamics on Reunion Island, Saint Denis, Reunion [ed. by Baret S, Rouget M, Nanni I, Bourgeois Le T]

Lavergne C, Radjassegarane S, Boullet V, Strasberg D, Florens V, Triolo J, 2003. [English title not available] . (Apport de la recherche dans les programmes de restauration écologique: l'exemple du projet de recherche "Invasions Biologiques INVABIO" a La Réunion) In: Proceedings of the regional workshop on invasive alien species and terrestrial ecosystem rehabilitation in Western Indian Ocean islands states [ed. by Mauremootoo J] Seychelles: COI/UICN/ISSG

Lourteig A, 1972. The genus Hedychium in Madagascar (Zingiberaceae). (Le genre Hedychium à Madagascar (Zingiberaceés)) Adansonia (ser. 2)., 121-127

Macdonald IAW, Thébaud C, Strahm W, Strasberg D, 1991. Effects of alien plant invasions on native vegetation remnants on La Réunion (Mascarene Islands, Indian Ocean). Environmental Conservation, 18:51-61

McCormack G, 2007. Cook Islands Biodiversity Database, Version 2007.2. Rarotonga: Cook Islands Natural Heritage Trust.

Missouri Botanical Garden, 2008. Tropicos database. St Louis, USA: Missouri Botanical Garden.

Mitra JN, 1958. Flowering plants of Eastern India. Calcutta, India: The World Press Private Ltd

Motooka P, Castro L, Nelson D, Nagai G, Ching L, 2003. Weeds of Hawaii's pastures and natural areas: an identification and management guide. Honolulu, HI, USA: College of Tropical Agriculture and Human Resources, University of Hawaii at Manoa, 184 pp

Naik VN, Panigrahi G, 1961. Genus Hedychium in Eastern India. Bulletin of the Botanical Survey of India, No. 3:67-73

Orchard AE, 1973. Zingiberaceae in New Zealand. Records of the Auckland Institute & Museum, No. 10:109-117

Orchard AE, 1978. Hedychium in New Zealand - a further name change. New Zealand Journal of Botany, 16:287-289

PIER, 2008. Pacific Islands Ecosystems at Risk. USA: Institute of Pacific Islands Forestry.

Queensland Department of Primary Industries and Fisheries, 2008. Whitei ginger - an emerging threat. White ginger - an emerging threat.

Radjassegarane S, 1999. Les plantes envahissantes de l'île de La Réunion. Etude de deux exemples: Hedychium flavescens (Zingiberaceae) et Ligustrum robustum subsp. walkeri (Oleaceae). Recherches préliminaires pour une lutte biologique. Toulouse, France: Université Paul Sabatier

Randall RP, 2002. A global compendium of weeds. A global compendium of weeds, xxx + 905 pp

Roscoe W, 1828. Monandrian Plants of the Order Scitamineae; Chiefly Drawn from Living Specimens in the Botanical Gardens at Liverpool

Royal Botanic Gardens Sydney, 2003. Australia's Virtual Herbarium. Sydney, Australia: Royal Botanic Gardens Sydney.

Royal Botanic Gardens Sydney, 2008. Australia's Virtual Herbarium. Sydney, Australia: Royal Botanic Gardens. http://avhtas.tmag

Smith CW, 1985. Impact of alien plants on Hawaii's native biota. In: Hawaii's terrestrial ecosystems: preservation and management. Proceedings of a symposium held June 5-6, 1984, at Hawaii Volcanoes National Park. [ed. by Stone CP, Scott JM] Honolulu, HI, USA: University of Hawaii Press, 180-250

Smith RM, 1983. Zingiberaceae. (Zingiberaceés) In: Flore des Mascareignes. La Réunion, Maurice, Rodrigues 171. Zingiberaceae à 176. Broméliacées [ed. by Bosser J, Cadet TH, Guého J, Marais W] Mauritius: Sugar Industry Research Institute, 1-16

Soares DJ, Barreto RW, 2008. Fungal pathogens of the invasive riparian Brazil and their potential for biological control. Fungal Diversity, 28:85-96

South African National Biodiversity Institute, 2008. Declared weeds/Invaders listed by common name.

Stainton A, 1988. Flowers of the Himalaya, a supplement. Oxford, UK: Oxford University Press

Timmins SM, MacKenzie IW, 1995. Weeds in New Zealand Protected Natural Areas Database. Department of Conservation Technical Series, 8. Wellington, New Zealand: Department of Conservation, 291 pp.

Turrill WB, 1914. Hedychium coronarium and allied species. Kew Bulletin:368-372

US Fish and Wildlife Service, 2006. Revised Recovery Plan for Hawaiian Forest Birds. In: Revised Recovery Plan for Hawaiian Forest Birds : US Fish and Wildlife Service.622 pp.

US Fish and Wildlife Service, 2009. `O`u (Psittirostra psittacea). 5-Year Review: Summary and Evaluation. In: `O`u (Psittirostra psittacea). 5-Year Review: Summary and Evaluation : US Fish and Wildlife Service.12 pp.

USDA-ARS, 2003. Germplasm Resources Information Network (GRIN). Online Database. Beltsville, Maryland, USA: National Germplasm Resources Laboratory.

USDA-ARS, 2008. Germplasm Resources Information Network (GRIN). Online Database. Beltsville, Maryland, USA: National Germplasm Resources Laboratory.

USDA-NRCS, 2008. The PLANTS Database. Baton Rouge, USA: National Plant Data Center.

Wagner WL, Herbst DR, Sohmer SH, 1999. Manual of the flowering plants of Hawaii. Revised edition. Honolulu, Hawaii, USA: University of Hawaii Press/Bishop Museum Press, 1919 pp

Williams PA, Nicol E, Newfield M, 2000. Science for Conservation. Wellington, New Zealand: Department of Conservation, 42 pp

Williams PA, Winks C, Rijkse W, 2003. Forest processes in the presence of wild ginger (Hedychium gardnerianum). New Zealand Journal of Ecology, 27(1):45-54

Winks CJ, Waipara NW, Smith LA, Tsai S, Wilkie JP, Peterson P, 2007. Invertebrates and Pathogens Associated with Wild Ginger, Hedychium gardnerianum and Hedychium flavescens (Zingiberaceae), in New Zealand. Landcare Research Contract Report LC0708/062

Witt, A., Luke, Q., 2017. Guide to the naturalized and invasive plants of Eastern Africa, [ed. by Witt, A., Luke, Q.]. Wallingford, UK: + 601 pp. doi:10.1079/9781786392145.0000

Wood TH, Whitten WM, Williams NH, 2000. Phylogeny of Hedychium and related genera (Zingiberaceae) based on ITS sequence data. Edinburgh Journal of Botany, 57(2):261-270

Wu TL, 1994. Phytogeography of the Zingiberaceae. Journal of Tropical and Subtropical Botany, 2(2):1-14

Links to Websites

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GISD/IASPMR: Invasive Alien Species Pathway Management Resource and DAISIE European Invasive Alien Species Gateway source for updated system data added to species habitat list.
Global register of Introduced and Invasive species (GRIIS) source for updated system data added to species habitat list.


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30/05/08 Original text by:

Djamila Djeddour, CABI Europe  - UK, Bakeham Lane, Egham, Surrey TW20 9TY

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