Genus Physcia
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The vegetative portion (thallus) of the Genus Physcia is leaf like, star-like, or sometimes with narrowly linear divisions, beneath it has usual fibres of varying length; the generic name is from the Greek; a blister, evidently referring to the inflated appearance of the thallus in some species.
The fruiting portion (apothecia) are shield-shaped, with the surface often covered with a whitish powder.
The spores are elliptical, brown, two-celled in our species.
Physcia Leucomela Lichen