Phaeophyscia

Phaeophyscia is a genus of lichen-forming fungi in the family Physciaceae.

Description
Genus Phaeophyscia encompasses a variety of lichen species, characterised by their leaf-like (foliose) structure that often extends in, which can either be short or elongate and tend to lie flat against the , resembling a loosely shrubby form in some instances. These lobes are typically less than 1.5 mm wide and have a range of colours from pale grey or greenish grey to dark brown, becoming dark green when moistened. The surface of these lichens is, not covered in a powdery coating , and usually lacks spots or fringe-like projections  along the edges. The underside is typically whitish or more commonly black, with matching, simple roots (rhizines) that may extend beyond the lobe tips, giving an appearance similar to cilia.

Some Phaeophyscia species develop soredia or isidia, specialised structures (propagules) used for asexual reproduction. The upper and lower layers of the thallus (cortex) are composed of closely packed cells, with the algal partner being –that is, from the green algal  genus Trebouxia. The reproductive organs (ascomata) are cup-shaped structures (apothecia) found on the lichen's surface, usually encircled by rhizines at their base, with a brown to black that lacks a powdery covering. The rim surrounding the reproductive disc is smooth and occasionally lobed.

Internally, the Phaeophyscia lichen has a brown upper layer, with colourless internal layers (hymenium and ). The supporting filamentous structures consist of slender, often branching paraphyses with club-shaped tips that are pale brown with a thin dark brown top. The spore-producing structures (asci) are approximately cylindrical to club-shaped, containing eight spores of the Lecanora-type. The spores themselves are brown, thick-walled, and divided by a single cross-wall (1-septate), resembling those found in the genus Physcia.

Asexual reproductive structures (conidiomata) are in the form of pycnidia, embedded within the lichen and mostly colourless, except for a brown area around the opening (ostiole). The asexual spores (conidia) are ellipsoidal in shape. In terms of chemical composition, Phaeophyscia lichens do not react to a solution of potassium hydroxide (K–) on the cortex and medulla, indicating the absence of atranorin. However, some species contain yellow to orange-red pigments that turn purple with potassium hydroxide (K+), known as skyrin, or terpenoids.

Ecologically, Phaeophyscia lichens favour nutrient-rich or enriched substrates in well-lit environments. They are distinguished from the closely related Hyperphyscia by their ellipsoidal, not thread-like, conidia, while Physcia species have rod-shaped conidia.

Species



 * Phaeophyscia adiastola (Essl.) Essl. (1978)
 * Phaeophyscia cernohorskyi (Nádv.) Essl. (1978)
 * Phaeophyscia ciliata (Hoffm.) Moberg (1977)
 * Phaeophyscia confusa Moberg (1983)
 * Phaeophyscia constipata (Nyl.) Moberg (1977)
 * Phaeophyscia crocea Aptroot & Sipman (1991)
 * Phaeophyscia culbersonii Essl. (2004)
 * Phaeophyscia dagestanica Urbanav. (2016)
 * Phaeophyscia decolor (Kashiw.) Essl. (1978)
 * Phaeophyscia denigrata (Hue) Moberg (1994)
 * Phaeophyscia echinata (Frey) N.S.Golubk. (1981)
 * Phaeophyscia endoaurantiaca (Barkh.) Schumm (2019)
 * Phaeophyscia endococcina (Körb.) Moberg (1977)
 * Phaeophyscia endococcinodes (Poelt) Essl. (1978)
 * Phaeophyscia endophoenicea (Harm.) Moberg (1977)
 * Phaeophyscia erythrocardia (Tuck.) Essl. (1978)
 * Phaeophyscia esslingeri S.Y.Kondr., Lőkös, J.J.Woo & Hur (2016)
 * Phaeophyscia exornatula (Zahlbr.) Kashiw. (1984)
 * Phaeophyscia fumosa Moberg (1983)
 * Phaeophyscia hirsuta (Mereschk.) Essl. (1978)
 * Phaeophyscia hirtella Essl. (1978)
 * Phaeophyscia hirtuosa (Kremp.) Essl. (1978)
 * Phaeophyscia hispidula (Ach.) Essl. (1978)
 * Phaeophyscia hunana G.R.Hu & J.B.Chen (2003) – China
 * Phaeophyscia imbricata (Vain.) Essl. (1978)
 * Phaeophyscia insignis (Mereschk.) Moberg (1978)
 * Phaeophyscia kairamoi (Vain.) Moberg (1977)
 * Phaeophyscia kashmirensis
 * Phaeophyscia laciniata Essl. (1979)
 * Phaeophyscia latifolia Kudratov (2002)
 * Phaeophyscia leana (Tuck.) Essl. (1978)
 * Phaeophyscia limbata (Poelt) Kashiw. (1984)
 * Phaeophyscia lygaea (Poelt) D.D.Awasthi (1988)
 * Phaeophyscia melanchra (Hue) Hale (1983)
 * Phaeophyscia microspora Aptroot & Schumm (2019)
 * Phaeophyscia nadvornikii (Frey & Poelt) N.S.Golubk. (1981)
 * Phaeophyscia nashii Essl. 2004)
 * Phaeophyscia nepalensis (Poelt) D.D.Awasthi (1988)
 * Phaeophyscia nigricans (Flörke) Moberg (1977)
 * Phaeophyscia opuntiella (Buschardt & Poelt) Hafellner (1992)
 * Phaeophyscia orbicularis (Neck.) Moberg (1977)
 * Phaeophyscia primaria (Poelt) Trass (1981)
 * Phaeophyscia pusilloides (Zahlbr.) Essl. (1978)
 * Phaeophyscia pyrrhophora (Poelt) D.D.Awasthi & M. Joshi (1978)
 * Phaeophyscia rubropulchra (Degel.) Moberg (1978)
 * Phaeophyscia saxatilis (Kashiw.) S.Y.Kondr. (2018)
 * Phaeophyscia sciastra (Ach.) Moberg (1977)
 * Phaeophyscia sonorae Essl. (2004)
 * Phaeophyscia spinellosa Kashiw. (1984)
 * Phaeophyscia squarrosa Kashiw. (1984)
 * Phaeophyscia stiriaca (Poelt) Clauzade & Cl.Roux (2001)
 * Phaeophyscia strigosa (Poelt & Buschardt) N.S.Golubk. (1981)
 * Phaeophyscia sulphurascens (Zahlbr.) Trass (1981)
 * Phaeophyscia ticinensis (Mereschk.) Schumm (2019)
 * Phaeophyscia trichophora (Hue) Essl. (1978)