Pycnora

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Pycnora is a small genus of lichen-forming fungi in the family Pycnoraceae. Austrian lichenologist Josef Hafellner first recognized this distinct group in the 1980s and formally established Pycnora as a genus, with Pycnora xanthococca as its type species. The family Pycnoraceae was later defined in 2013 by Bendiksby and Timdal.

Habitat and appearance
- Pycnora lichens live on dead wood in cool northern and mountain forests.
- They form thin, grey crusts on smooth, bark-less surfaces of fallen trunks and branches.
- The most noticeable feature is the black fruiting bodies (apothecia) on the thallus, plus scattered black pycnidia (aerial spore-producing structures).

Key identifying features
- Crustose thallus with a pale to dark grey surface.
- Black apothecia with a narrow thalline exciple.
- Scattered black pycnidia that release asexual spores.
- Lecanora-type asci: eight spores per ascus, each spore single-celled and roughly oval.
- The thallus and its chemistry are dominated by alectorialic acid derivatives.

Chemistry and relatives
- All known Pycnora species produce alectorialic acid derivatives, a chemical that helps distinguish it from similar crustose lichens.
- Pycnora differs from related genera by its black apothecia, eight-spored Lecanora-type asci, single-celled ascospores, and its alectorialic acid chemistry.
- In comparisons, Pycnora is set apart from Hypocenomyce (Bacidia-type asci, different chemistry), Ramboldia (different pycnidia and chemistry), and pycnidiate Cliostomum (Bacidia-type asci).

Species
- Pycnora praestabilis
- Pycnora sorophora
- Pycnora xanthococca (type species)

Notes
- A species formerly placed in Pycnora, Pycnora leucococca, has been moved to the genus Toensbergia (as Toensbergia leucococca).