Kahili ginger
Hedychium gardnerianum
Family · Zingiberaceae · Harmless
The worst invader in the Azores and one of the worst in the world. It comes from the Himalayas, was planted for being pretty, and today covers whole valleys with a mat of rhizomes through which nothing else comes up.
Oak woods · Streams and ditches · Roadsides and waste ground · Uplands
Also known askahili ginger, wild ginger
How to tell it
A plant one to two metres, with large lance-shaped leaves set in two ranks along a fleshy stem, like a small banana plant. A dense terminal spike with pale yellow flowers and very prominent bright red stamens, strongly scented. Thick orange rhizomes forming a continuous mat.
What it is confused with
No dangerous lookalikes known in the Iberian Peninsula.
What it is for
None. It is the species that consumes the most public money in control in the Azores and the one that has most reduced viable laurisilva. A rhizome fragment the size of a finger starts a new patch, so not even pulled up is it carried away.
The law says
A listed invasive alien species in Portugal and on the European Union list. Do not plant it, propagate it, or carry rhizomes or seeds.