![cover image](https://wikiwandv2-19431.kxcdn.com/_next/image?url=https://upload.wikimedia.org/wikipedia/commons/thumb/2/24/Usnea_filipendula_170406a.jpg/640px-Usnea_filipendula_170406a.jpg&w=640&q=50)
Outline of lichens
Symbiosis of fungi with algae or cyanobacteria / From Wikipedia, the free encyclopedia
The following outline provides an overview of and topical guide to lichens.
![An intricately branched, pale green lichen hangs from a branch.](http://upload.wikimedia.org/wikipedia/commons/thumb/2/24/Usnea_filipendula_170406a.jpg/640px-Usnea_filipendula_170406a.jpg)
Lichen – composite organism made up of multiple species – a fungal partner, one or more photosynthetic partners, which can be either green algae or cyanobacteria, and, in at least 52 genera of lichens, a yeast.[1] In American English, "lichen" is pronounced the same as the verb "liken" (/ˈlaɪkən/). In British English, both this pronunciation and one rhyming with "kitchen" (/ˈlɪtʃən/) are used.[2]