thallus_surface_cracking
cracked|cracks
margin entire, soon becoming cracked; later cracks extensive, often delimiting discrete areoles; areoles plane, 330-670 µm diameter, with black sides; cells weakly delimited vertical columns; air spaces present; upper surface pseudocortex with dull brown pigment; lower part often darkly pigmented, sometimes forming a thick dark basal layer; cells contain large oil droplets
Willeya irrigata
Willeya irrigata