Thecographa
{{Short description|Genus of lichens}}
{{Use dmy dates|date=May 2024}}
{{Automatic taxobox
| image =
| taxon = Thecographa
| authority = A.Massal. (1860)
| type_species = Thecographa prosiliens
| type_species_authority = (Mont. & Bosch) A.Massal. (1860)
| synonyms = *Emblemia {{au|Pers. (1827)}}
- Megalographa {{au|A.Massal. (1860)}}
- Phaeographina {{au|Müll.Arg. (1882)}}
- Phaeographinomyces {{au|Cif. & Tomas. (1953)}}
| subdivision_ranks = Species
| subdivision = T. ceramia
}}
Thecographa is a genus of lichen-forming fungi in the family Graphidaceae. It has three species of corticolous (bark-dwelling) script lichens. The genus was circumscribed by Abramo Bartolommeo Massalongo in 1860. Although Massalongo did not assign a type species for the genus, David L. Hawksworth set Thecographa prosiliens as the type in 1981. Morphological characteristics of the genus include its {{lichengloss|sessile}} {{lichengloss|lirella}} (fruiting bodies), the lack of a {{lichengloss|thalline margin}}, and the complete {{lichengloss|carbonisation}} of the {{lichengloss|excipulum}}.
Description
The genus Thecographa features apothecia (fruiting bodies) that are initially closed and embedded ({{lichengloss|hypophloedal}}), but later erupt to become open, elevated, and urn-shaped ({{lichengloss|urceolate}}). These apothecia often appear almost stalked, and are characteristically flexible, twisted, and angular. They are rarely and sparsely branched. The apothecia are equipped with a distinctive, {{lichengloss|carbonaceous}} excipulum that is cup-shaped. This structure is thin but consistent, enveloped by the thallus or tree bark on which the lichen lives. Over time, the covering epidermis may gradually disappear.
The {{lichengloss|disc}} of the apothecia is gelatinous, flattened, and tends to lose its colour, supported by a solid, almost papery base known as the {{lichengloss|hypothecium}}. The asci (spore-producing structures) are club-shaped and contain 2-4-8 spores, accompanied by paraphyses (sterile filaments interspersed among the asci). The spores are elliptical or ovoid, {{lichengloss|muriform}} (with multiple divisions), initially transparent but becoming cloudy and opaque over time. The thallus of Thecographa is spread out and irregularly shaped, embedding itself into the {{lichengloss|substrate}}.
Species
- Thecographa ceramia {{au|A.Massal. (1860)}}
- Thecographa crassilabra {{au|(Mont. & Bosch) A.Massal. (1860)}}
- Thecographa prosiliens {{au|(Mont. & Bosch) A.Massal. (1860)}}
References
{{Reflist|refs=
{{Catalogue of Life |id=7VGZ |title=Thecographa |access-date=9 May 2024}}
{{cite web |title=Synonymy. Current Name: Thecographa A. Massal., Atti Inst. Veneto Sci. lett., ed Arti, Sér. 3 5: 316 (1860) [1859-1860]|url=https://www.speciesfungorum.org/Names/SynSpecies.asp?RecordID=5415 |publisher=Species Fungorum |access-date=9 May 2024}}
}}
{{Taxonbar|from=Q107289461}}