Description

A lichen is a composite organism, a stable symbiotic partnership between:

• fungus (mycobiont)
• alga or cyanobacterium (photobiont)

Some lichens have highly organized internal layers; others form a uniform, gelatinous body.

They absorb water, minerals, and atmospheric nutrients directly across their surface.

When growing on trees, they are not parasitic — they use bark only as a physical surface. Lichens possess characteristics that set them apart from plants, fungi, and other organisms.

Though often described as “plant-like” — with leaf-like lobes or branching structures — lichens are not plants. They do not have roots, stems, or vascular tissues, and they do not draw nutrients from the substrate they grow on.