Fungalpedia – Note 2586, Lichenostigma
Lichenostigma Hafellner.
Citation when using this data: Meng QF et al. – Fungalpedia.
Index Fungorum, Facesoffungi, MycoBank, GenBank Figure 1, 2
Classification: Phaeococcomycetaceae, Lichenostigmatales, Arthoniomycetes, Pezizomycotina, Ascomycota, Fungi
Lichenostigma was introduced by Hafellner (1983) to describe the lichenicolous fungus L. maureri. Initially, this genus was placed within Athroniales based on the type of its asci. To clarify its phylogenetic position, Ertz et al. (2014) conducted a comprehensive analysis using LSU and mtSSU from both the sexual and asexual stages of various genera. The phylogenetic analyses revealed that these species form two primary lineages, one of which was a poorly supported clade comprising the genera Phaeococcomyces and Lichenostigma. As a result, the new order Lichenostigmatales was proposed to accommodate Phaeococcomycetaceae. This family includes the black yeast genus Phaeococcomyces, along with two genera producing both ascomata and conidiomata, Etayoa and Lichenostigma. Additionally, two new species were described, and three Phaeosporobolus species were reassigned to Lichenostigma (Ertz et al. 2014).
The genus is distinguished by its dark brown to blackish, dispersed stromata, which are initially subspherical but later become elongate. The asci are subspherical to shortly ellipsoid, (4–)8-spored, with a thickened apical wall and a distinct ocular chamber. The ascospores are hyaline when young, with the outer wall occasionally reacting K/I+ blue, and become hyaline or dark brown with age. They are 1-septate, ellipsoid to elongate, with rounded or attenuated, sometimes pointed apices. Its conidiomata are often intermixed with ascomata and macroscopically indistinguishable, although they are sometimes smaller. Conidiogenous cells are pale to medium brown, developing from spherical stromatic cells. They are shortly subcylindrical to almost ellipsoid, with an indistinctly truncate base. The conidia are multicellular, composed of the conidiogenous cell and additional conidial cells. They are ellipsoid, brown, and smooth but may exhibit a verrucose to echinulate ornamentation when over-mature. Conidia are dry, solitary, and undergo schizolytic secession (Ertz et al. 2014).
To date, 35 species are recognized in this genus, all of which are lichenicolous, and 24 sequences available in GenBank, include LSU, SSU and mtSSU.
Type species: Lichenostigma maureri Hafellner, on Usnea and other macrolichens.
Other accepted species: Species Fungorum – search Lichenostigma
Figure 1 – Lichenostigma maureri redrawn from Hafellner (1983) and Ertz et al. (2014). a Ascomata on the thallus of Usnea hirta. b Section of Apothecium. c Asci (mature and immature). d Ascospores. Scale bars: b = 20 μm, c–d = 10 μm.
Figure 2 – Asexual stage of Lichenostigma maureri redrawn from Hawksworth et al. (1986). a Vertical section of portion of Stroma; b Multicellular conidia; c Developing conidia showing conidiogenous cells. Scale bars: c = 10 μm.
References
Entry by
Meng QF, Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, 57100, Thailand and School of Public Health, Zunyi Medical University, Guizhou 563000, China
Published online 9 June 2026