Squamulose lichen

A squamulose lichen is a lichen that is composed of small, often overlapping "scales" called squamules.^[1] If they are raised from the substrate and appear leafy, the lichen may appear to be a foliose lichen, but the underside does not have a "skin" (cortex), as foliose lichens do. ^[2] Squamulose lichens are composed of flattish units that are usually tightly clustered. They are like an intermediate between crustose and foliose lichens.

Placidium arboreum is a squamulose lichen with squamules that become green when wet.

Examples of squamulose lichens include Vahliella leucophaea, Cladonia subcervicornis and Lichenomphalia hudsoniana.^[3]