A genus of lichens, in which the thallus is foliose to sub-fruticose with radiating lobes; the upper surface is typically grey-green. Both surfaces are covered by a cortex. Rhizines are absent. Species are found on a range of substrates in cooler regions. Hypogymnia physodes is one of the commoner British lichens, and is fairly insensitive to atmospheric pollution.
Subjects: Plant Sciences and Forestry.