Physciaceae
The Physciaceae are a family of mostly lichen-forming fungi belonging to the class Lecanoromycetes in the division Ascomycota. A 2016 estimate placed 19 genera and 601 species in the family.
Taxonomy
Physciaceae was formalised by Alexander Zahlbruckner in Adolf Engler's Syllabus, with Physcia as the type genus. In a set of conservation proposals intended to stabilise long-used family names, Hawksworth and Eriksson recommended conserving Physciaceae against the earlier name Pyxinaceae, arguing that Pyxinaceae had not been taken up in standard works and that Physciaceae was firmly established in the literature. They characterised Physciaceae as one of the major families of the Lecanorales, then comprising about 20 genera and roughly 850 species, many of them familiar macrolichens.Hawksworth and Eriksson also noted historical alternatives that do not displace Physciaceae: Körber's "Anaptychiaceae" proved to be a tribal-rank usage without a, so it was not validly published; had it been valid and pre-1898, it would likewise have required conservation of Physciaceae over that name.
Description
The Physiaceae includes various growth forms such as foliose, fruticose,, stipitate, crustose, and even evanescent types. Some members of this family may also be lichenicolous, meaning they grow on other lichens. These lichens can exhibit features such as, isidia, and soredia, or may lack them entirely.The upper of Physiaceae lichens can be,, or absent. Their photobiont, or the symbiotic algae living within the lichen, is typically a unicellular green alga from the genus Trebouxia, with a diameter ranging from 5 to 20 μm. The medulla can vary from poorly to well-developed or may even be absent, and it often contains lichen substances. The lower cortex can be prosoplectenchymatous, paraplectenchymatous, or absent, with the lower surface either possessing or lacking rhizines. A prothallus may be present or absent.
Physiaceae lichens produce ascomata, which can be either apothecia or. Their apothecia can be immersed, sessile, or short-stalked, with a more or less distinct exciple. The, when present, is generally round and ranges from flat to convex, displaying colours from brown to dark reddish-brown or black. A may or may not be present, while the can be thin and weakly pigmented or well-developed and darkly pigmented.
The can be brown-black, brown, or green, while the hymenium is colourless or partly green, with or without oil droplets. The can vary in colour from colourless to yellow-brown, brown, or dark brown. are simple or sparingly branched in the uppermost part, with thickened apices often capped by a brown-pigmented layer. The asci are, typically with 8 spores and a well-developed amyloid, a paler conical axial mass, and an ocular chamber.
Ascospores in the Physiaceae have a single septum, olive to brown in colour, and ellipsoidal in shape, often displaying uneven wall thickenings. The conidiomata are, either immersed or superficial. can be formed acrogenously or pleurogenously, and they can be ellipsoidal,,, or.
Genera
This is a list of the genera contained within the Physciaceae, based on a 2020 review and summary of ascomycete classification; as well as several genera that have been circumscribed or resurrected since then. Following the genus name is the taxonomic authority, year of publication, and the number of species:- Anaptychia – about 15 spp.
- Awasthia – 1 sp.
- Coscinocladium – 2 spp.
- Helmutiopsis – 3 spp.
- Heterodermia – about 90 spp.
- Huriopsis – 7 spp.
- Hyperphyscia – 9 spp.
- Johnsheardia – 5 spp.
- Kashiwadia – 1 sp.
- Klauskalbia – 4 spp.
- Kudratovia – 8 spp.
- Kurokawia – 7 spp.
- Leucodermia – 10 spp.
- Mischoblastia – 3 spp.
- Mobergia – 1 sp.
- Oxnerella – 1 spp.
- Phaeophyscia – 66 spp.
- Phaeorrhiza – 2 spp.
- Physcia – about 80 spp.
- Physciella – 4 spp.
- Physconia – about 25 spp.
- Polyblastidium – 18 spp.
- Rinodina – about 300 spp
- Rinodinella – 6 spp.
- Tornabea – 1 spp.