Cryptoschizotrema

Cryptoschizotrema is a genus of lichen-forming fungi in the family Graphidaceae. It has two species.^[1][2] The genus was circumscribed in 2019 by lichenologists André Aptroot, Robert Lücking, and Marcela Cáceres. The genus name alludes to the similarity in anatomy with Schizotrema species. This resemblance is due to the partially , concentrically layered, and fissured , which gives the impression that the Schizotrema-like excipulum is concealed beneath a protective layer. The type species was originally described by William Nylander in 1867, as a species of Thelotrema.^[3]

Description

The ascomata of Cryptoschizotrema lichens are immersed- and rounded, with the concealed beneath a narrow pore. The is hidden by a whitish thalline layer, and when abraded, it reveals brown to black fissured that form concentric layers in older specimens. Notably, a is absent in this genus. The of Cryptoschizotrema is , displaying a dark brown colour that may partially towards its apex. As the ascomata mature, the excipulum develops distinct layers or striations. , however, are not present.^[3]

The hymenium of this lichen is transparent, featuring unbranched . are typically found in quantities of one to two, though occasionally up to four per ascus. These ascospores are , measuring up to 100 by 30 μm, and have an oblong to ellipsoid shape. The , with relatively thin walls and septa, along with angular , contribute to the ascospores' colourless appearance. Additionally, they are I-negative, indicating their non-amyloid nature. The secondary chemistry of the genus is characterized by the presence of psoromic acid, which causes the thallus to display a P+ (yellow) reaction with standard chemical spot tests.^[3]

Species

Species in this genus occur in Central and South America.

• Cryptoschizotrema cryptotrema
• Cryptoschizotrema minus ^[4]

References

1. ^
2. ^ Wijayawardene, N.N.; Hyde, K.D.; Dai, D.Q.; Sánchez-García, M.; Goto, B.T.; Saxena, R.K. et al. (2022). "Outline of Fungi and fungus-like taxa – 2021". Mycosphere. 13 (1): 53–453 [160]. doi:10.5943/mycosphere/13/1/2. hdl:10481/76378. S2CID 249054641
3. ^ Hyde, Kevin D.; Tennakoon, Danushka S.; Jeewon, Rajesh; Bhat, D. Jayarama; Maharachchikumbura, Sajeewa S. N.; Rossi, Walter et al. (2019). "Fungal diversity notes 1036–1150: taxonomic and phylogenetic contributions on genera and species of fungal taxa". Fungal Diversity. 96 (1): 1–242. doi:10.1007/s13225-019-00429-2. S2CID 195329389
4. ^ de Lima, Edvaneide Leandro; Maia, Leonor Costa; Barroso Martins, Mônica Cristina; da Silva, Nicácio Lima; Lücking, Robert; da Silva Cáceres, Marcela Eugenia (2019). "Five new species of Graphidaceae from the Brazilian Northeast, with notes onDiorygma alagoense". The Bryologist. 122 (3): 414–422. doi:10.1639/0007-2745-122.3.414. S2CID 202855598