A squamulose lichen is a

lichen A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...

that is composed of small, often overlapping "scales" called . If they are raised from the substrate and appear leafy, the lichen may appear to be a

foliose lichen A foliose lichen is a lichen with flat, leaf-like , which are generally not firmly bonded to the substrate on which it grows. It is one of the three most common growth forms of lichens. It typically has distinct upper and lower surfaces, each o ...

, but the underside does not have a "skin" (

cortex Cortex or cortical may refer to: Biology * Cortex (anatomy), the outermost layer of an organ ** Cerebral cortex, the outer layer of the vertebrate cerebrum, part of which is the ''forebrain'' *** Motor cortex, the regions of the cerebral cortex i ...

), as foliose lichens do. Squamulose lichens are composed of flattish units that are usually tightly clustered. They are like an intermediate between

crustose Crustose is a Habit (biology), habit of some types of algae and lichens in which the organism grows tightly appressed to a substrate, forming a biological layer. ''Crustose'' adheres very closely to the Substrate (biology), substrates at all poin ...

and foliose lichens. Examples of squamulose lichens include '' Vahliella leucophaea'', '' Cladonia subcervicornis'' and '' Lichenomphalia hudsoniana''.

References

Lichenology {{lichen-stub