Phyllocraterina

Phyllocraterina is a small genus of lichen-forming fungi in the family Strigulaceae.^[2] It comprises two species of leaf-dwelling (foliicolous) lichens.^[3]

Phyllocraterina
Scientific classification
Domain:	Eukaryota
Kingdom:	Fungi
Division:	Ascomycota
Class:	Dothideomycetes
Order:	Strigulales
Family:	Strigulaceae
Genus:	Phyllocraterina Sérus. & Aptroot (2020)
Species
P. nuda P. papuana
Synonyms[1]
Phyllocratera Sérus. & Aptroot (1997)

Taxonomy

The genus was first proposed as Phyllocratera by the lichenologists Emmanuël Sérusiaux and André Aptroot in 1997.^[4] This name, however, was later deemed illegitimate under Article 53.1 of the International Code of Nomenclature for algae, fungi, and plants, due to prior use in botany. A similar name, Phyllocrater Wernham, had been established in 1914 for a genus in the family Rubiaceae.^[5] The Nomenclature Committee for Fungi determined that the similarity between Phyllocratera and Phyllocrater constituted a case of parahomonymy, leading to its invalidation.^[6] As a result, Sérusiaux and Aptroot established Phyllocraterina as a replacement name, publishing it alongside the type species Phyllocraterina papuana. While the genus currently includes two species, molecular data are not yet available for either.^[6]

Description

Phyllocraterina species are tropical lichens that grow on the surfaces of leaves in lowland to montane regions. Their thalli (lichen bodies) are thin, grey-green, and slightly crust-like, forming a close bond with their green algae partner, Phycopeltis. The reproductive structures (the perithecia) are black and wart-like, with a broad base and a small pore at the top for spore release. These structures have tough, carbon-rich walls and a protective outer layer.^[6]

Inside the perithecia, there are slender, unbranched filaments (paraphyses) that are clear and measure about 1.5–2 micrometres wide. The spore-producing cells (asci) contain eight spores each. These asci are structured in a way that allows them to split open for spore release. The spores themselves are transparent, have multiple internal walls, and are shaped like elongated ellipses with a slight pinch at the middle. So far, no form of asexual reproduction has been observed, and no chemical compounds (lichen products) unique to these lichens have been detected.^[6]

Species

• Phyllocratera nuda (Zahlbr.) Lücking & Sérus. (2013)
• Phyllocratera papuana Sérus. & Aptroot (1997)