Fungalpedia – Note 2604, Hemigrapha
Hemigrapha (Müll. Arg.) R. Sant. Ex D. Hawksw.
Citation when using this data: Meng QF et al. – Fungalpedia.
Index Fungorum, Facesoffungi , MycoBank, GenBank, Fig 1, 2.
Classification: Hemigraphaceae, Asterinales, Dothideomycetes orders incertae sedis, Pezizomycotina, Ascomycota, Fungi
Hemigrapha was initially established by Müller (1882) as a section of Melanographa Müll. Arg. Hawksworth (1975) transferred the species Melanographa astericus Müll. Arg. To Hemigrapha asteriscus (Müll. Arg.) R. Sant. Ex D. Hawksw., which grows on Sticta dufourii Del. From the Northern Hemisphere, and was designated as the type species (Müller 1882, Hawksworth 1975a). The genus is characterized by dark, superficial, star-shaped ascomata forming on a thallus of lichens, clavate to subglobose asci, and brown, ellipsoid, 2-celled ascospores. The conidiomata are pycnothyria, with holoblastic, discrete, determinate conidiogenous cells that are subspherical, ellipsoid to shortly ampulliform, simple or rarely 1-septate, hyaline, smooth, and lacking proliferations. Conidia are hyaline, aseptate, smooth, with a truncate or non-truncate base, and are of two types: narrowly ellipsoid to rod-shaped microconidia and larger, ellipsoid macroconidia (Diederich et al. 2000b).
The taxonomic position of Hemigrapha has undergone several changes. Eriksson et al. (1991) tentatively proposed its placement in the Hysteriaceae (Dothideales), acknowledging the provisional nature of this classification. Diederich et al. (2000) proposed placing this genus in Microthyriaceae (Dothideales) based on its thyriothecial ascomata with radiating rows of cells, the hamathecium formed of paraphysoids, the fissitunicate asci not becoming blue in iodine, and the mostly 1-septate ascospores. Eriksson et al. (2001) transferred this genus to Parmulariaceae with a question mark. Hyde et al. (2013) included the genus in Parmulariaceae but explained that it is incertae sedis until the molecular data is available. Ertz & Diederich (2015) conducted the first phylogenetic analysis of Dothideomyceta based on LSU and mtSSU data sets. Two Hemigrapha species were included in the phylogenetic tree, and Hemigrapha atlantica forms a single clade clustering within Asterinales (Ertz et al. 2015a). Consequently, Dai et al. (2018) introduced the new family Hemigraphaceae to accommodate this single genus. Wijayawardene et al. (2022) included this genus within Hemigraphaceae (Asterinales)
To date, nine species are recognized in this genus, all of which are lichenicolous. After Hawksworth (1975) published the first combined species, Matzer (1996) introduced two new species, Hemigrapha phaeospora Matzer & Lücking growing on Pseudocyphellaria and Hemigrapha strigulae Matzer growing on Strigula, and one combination Hemigrapha tenellular (Müll. Arg.) R. Sant. Ex Matzer from Melanographa tenellula Müll. Arg. Diederich & Wedin (2000) revised Hemigrapha growing on Peltigerales and discussed the taxonomic position of this genus. Three new species, Hemigrapha atlantica Diederich & Wedin, growing on Sticta canariensis (Bory) Bory ex Delise, H. nephromatis Wedin & Diederich, growing on Nephroma australe A. Rich., and H. pseudocyphellariae Diederich & Wedin, growing on Pseudocyphellaria argyracea (Delise) Vain. Were introduced simultaneously. Cáceres & Lücking (2000) introduced Hemigrapha pilocarpacearum M. Cáceres & Lücking, which grows on the lichen Byssoloma minutissimum Kalb & Vězda. The latest new species is Hemigrapha graphidicola Diederich & Common, growing on Graphis assimilis Nyl., introduced by Diederich et al. (2019).
Type species: Hemigrapha asteriscus (Müll. Arg.) R. Sant. Ex D. Hawksw.
Other accepted species: Species Fungorum – search Hemigrapha
Figure 1 – Sexual morph of Hemigrapha asteriscus redrawn from Diederich et al. (2000b), Dai et al. (2018). a Appearance of ascostromata. b, c Section of ascostromata. d, e Asci. f, g Ascospores. Scale bars: a = 500 μm, b–c = 50 μm, d–g = 5 μm.
Figure 2 – Asexual morph of Hemigrapha asteriscus redrawn from Diederich et al. (2000b), a Macroconidial morph. b Microconidial morph. Scale bars: a, b = 10 μm.
References
Eriksson O, Baral H-O, Currah RS, Hansen K et al. 2001 – Notes on ascomycete systematics Nos. 3128–3302. Myconet 6, 1–26.
Eriksson OE, Hawksworth DL. 1991 – Outline of the ascomycetes-1990. Systema Ascomycetum 9, 39–271.
Matzer M. 1996 – Lichenicolous ascomycetes with fissitunicate asci on foliicolous lichens. Mycological Papers 171, 1–202.
Müller J. 1882 – Lichenologische Beiträge XVI. Flora (Regensburg) 65 (33), 515–519.
Hawksworth DL. 1975a – Notes on British lichenicolous fungi: I. Kew Bulletin 30 (1), 183–203.
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 16 June 2026