Hedychium flavescens Carey ex Roscoe

Madagascar: Hedychium flavescens flowers and fructifies, from March to July.
Mayotte : Hedychium flavescens flowers from April to Ocotber and fruits from May to November.

Hedychium flavescens is a vivacious species; it abundantly multiplies vegetatively by rhizomes at the soil surface. It also produces many seeds but it is difficult to find fertile seeds.

Hedychium flavescens is a plant of the humid tropical region. It grows in agricultural areas, natural humidforests, planted forests, forest galleries; it is also present as ruderal species in disturbed areas and along roads. H. flavescens requires soil with average to high fertility, and prefers to grow in open environments, bright, warm and humid but it can easily colonize the semi-shade and forest cover.
 
Comoros: Species present in rainforest at average altitude in the ancient fields of banana trees.
Madagascar: The species grows on alluvial soils, and the ferralitic soils that are quite fertile in humid places, along rivers and canals, at the edge of crops, in humid zones up to 1200 m altitude but especially below 500m, in sunny or slightly shady places. It is a weed of extensive farming systems, in rice cultivation and in perennial crops at the bottom of the slope.
Mauritius: The plant is naturalized on the island and is frequently found in humid areas.
Mayotte: Hedychium flavescens is an exotic species rarely cultivated as an ornamental plant and locally naturalized, especially along waterways.
Reunion: Plant naturalized on the island and is frequently found in humid areas in ravines, on roadsides, near the native forest and disturbed forest. It is an invasive species along the rivers and forest, from humid lowland forest into the humid mountain forest.

Worldwide distribution

This species is widely cultivated in tropical and subtropical regions where it has naturalized: Asia (China, Vietnam, Sri Lanka) Africa (Comoros, Madagascar, Mascarene Islands, South Africa), North America (Hawaii), Central America ( Puerto Rico), Europe (Azores), Oceania (Australia, Fiji, Cook islands, Polynesia, Guam, Micronesia, New Caledonia, New Zealand, Niue, Samoa, Tonga).

Hedychium flavescens is a major invasive species along the banks of rivers, natural forests and forest edges. This is not a weed of crops. It is an invasive species that threatens the environment, indigenous communities and biodiversity.

Local harmfulness

Comoros: highly invasive species, common in humid mid-elevation environments. It colonizes ruderal areas, particularly along the paths and open spaces. It is a weed in the ancient fields of banana at medium altitude. This species takes very quickly the spaces formerly cultivated and accompanies the old cultures of banana and taro in undergrowth.
Madagascar: H. flavescens is a scarce weed in crops but locally abundant at the edge of crops, along the edges of canals and streams in wetlands (eastern side of the island).
South Africa: Hedychium flavescens competes with and replaces native species. It hinders access to plantations. It is present in the provinces of Gauteng, Eastern Cape, Western Cape, Kwa-Zulu Natal and Free State.

Herbarium pictures ReCOLNAT: https://explore.recolnat.org/search/botanique/simplequery=Hedychium%2520flavescens