Fellhaneropsis

''Fellhaneropsis'' is a genus of lichen-forming fungi in the family Pilocarpaceae. The genus comprises 11 accepted species as of 2025. These inconspicuous lichens form extremely thin, smooth to powdery films that spread over bark, leaves, or other plant surfaces, and unlike their close relatives in ''Fellhanera'', they produce no detectable lichen products.

Taxonomy

The genus was circumscribed by Emmanuël Sérusiaux and Brian John Coppins in 1996, with '' F. myrtillicola'' assigned as the type species. It is named in honour of the Austrian lichenologist Josef Hafellner.

Description

''Fellhaneropsis'' species form an extremely thin, crust-like thallus that sits flush against the substrate and lacks any protective outer skin (). The surface is usually smooth to slightly powdery and varies from whitish to dull grey-green, spreading in inconspicuous films over bark, leaves or other plant material. The internal partner is a simple alga—tiny, spherical cells 5–12 Î¼m in diameter—that are evenly dispersed through the fungal tissue. Because there is no distinct (the dark border seen in some crusts), colonies merge almost imperceptibly into the underlying surface.

Sexual reproduction occurs in small, stalkless apothecia measuring 0.1–0.4 mm across. Each fruit body is pinched in at the base and loses its thin rim early, leaving a flat to slightly convex . The disc's wall, or , is a delicate layer of rounded to polyhedral cells arranged more or less upright rather than in the densely interwoven 'brickwork' typical of many lichens. Inside, colourless paraphyses branch and link together, surrounding club-shaped asci that contain eight ascospores. Both the ascus tip and its gelatinous outer coat stain blue in iodine—an amyloid reaction. The spores are long and needle-to-spindle-shaped, divided by three to seven cross-walls, and sometimes wrapped in a faint, jelly-like sheath.

Asexual reproduction takes place in minute pycnidia sunk into the thallus. These flask-shaped structures are ringed by upright, fringe-like hyphae around the pore (ostiole) and usually release one type of conidium: a very slender, thread-like spore with no internal walls. In ''F. myrtillicola'' a second, shorter conidium is also produced. No secondary lichen substances have so far been detected in the genus, setting ''Fellhaneropsis'' apart from its chemically positive relative ''Fellhanera''.

Species

, species Fungorum (in the Catalogue of Life) accept 11 species of ''Fellhaneropsis'':
* '' Fellhaneropsis almquistiorum''
* '' Fellhaneropsis australiana'' – Australia
* '' Fellhaneropsis humicola'' – Australia
* '' Fellhaneropsis kurokawana'' – Japan
* '' Fellhaneropsis macrocarpa'' – Australia
* '' Fellhaneropsis myrtillicola''
* '' Fellhaneropsis pallidonigrans''
* '' Fellhaneropsis rhododendri'' – Europe
* '' Fellhaneropsis subantarctica''
* '' Fellhaneropsis tasmanica'' – Australia
* '' Fellhaneropsis vezdae''

References

{{Taxonbar, from=Q5442464

Pilocarpaceae
Lichen genera
Lecanorales genera
Taxa named by Brian John Coppins
Taxa named by Emmanuël Sérusiaux
Taxa described in 1996