Fungalpedia – Note 2673, Corticifraga
Corticifraga D. Hawksw. & R. Sant.
Citation when using this data: Meng QF et al. – Fungalpedia.
Index Fungorum, Faceoffungi, MycoBank, GenBank, Fig 1.
Classification: Gomphillaceae, Graphidales, Ostropomycetidae, Lecanoromycetes, Pezizomycotina, Ascomycota, Fungi.
The obligately lichenicolous genus Corticifraga was introduced by Hawksworth & Santesson (1990) to accommodate the type species C. peltigera, which primarily grows on Peltigera and occasionally on Solorina and Pseudocyphellaria. It is characterized by its lichenicolous, commensalistic, or parasitic lifestyle and is non-lichenized. The ascomata are initially nearly perithecioid or lens-shaped, breaking through the host cortex and eventually becoming apothecioid, concave to plane, fawn to black, occurring solitarily or in small groups, and are immersed. The exciple is hyaline to dark olivaceous brown, composed of irregular, subglobose to ± elongated pseudoparenchymatous cells. The paraphyses are filiform, simple or sparsely branched, and septate. The asci are broadly clavate with a short stalk, featuring two distinct wall layers, a truncated and thickened apex, and discharge through a short extension of the inner apical tissues without amyloid reactions, containing eight spores. The ascospores are hyaline, broadly fusiform to ellipsoid or soleiform, often tapered at the base, smooth, 1–3-septate, distichously arranged, and lack of a perispore (Ertz 2004).
Hawksworth et al. (1990) suggested that Corticifraga could belong to Ostropales due to its non-amyloid asci. However, Ertz (2004) proposed placing this genus within Lecanorales, though with some uncertainty. Lumbsch et al. (2007) classified this genus within Lecanoromycetes genera incertae sedis. It wasn’t until Pino-Bodas et al. (2017) conducted a phylogenetic study on lichenicolous fungi associated with Cladonia and other genera that the type species Corticifraga peltigerae was sequenced and included in a phylogenetic analysis. This analysis placed the genus within Ostropales, closely related to Actinoplaca strigulacea in Graphidaceae, subfamily Gomphilloideae (Pino-Bodas et al. 2017), a classification later accepted by Wijayawardene et al. (2022). Hyde et al. (2024) placed Gomphillaceae within Graphidales, and Lebreton et al. (2025) confirmed the placement according to the phylogenetic analysis based on three genes sequence dataset (LSU, mtSSU and RPB1).
Initially, Corticifraga was primarily found on Peltigera, with occasional occurrences on Solorina and Pseudocyphellaria. Zhurbenko (2007a) introduced two additional species: Corticifraga chugachiana, which grows on Lobaria, and C. santessonii, which grows on Nephroma occultum. Most of the newly described species are found on foliose lichens, except for C. ramalinae, which grows on the fruticose lichen Ramalina fraxinea (Roux 2022). To date, there are ten species in this genus, all of which are lichenicolous.
Type species: Corticifraga peltigerae (Fuckel) D. Hawksw. & R. Sant.
Other accepted species: Species Fungorum – search Corticifraga.
Figure 1 – Corticifraga peltigerae redrawn from Puolasmaa et al. (2012). a Paraphyses. b Asci. c Ascospores. Scale bars: a, b = 20 μm, c = 10 μm.
References
Ertz D 2004 – Corticifraga. in Nash III, TH, Ryan, BD, Diederich, P, Gries, C et al.,Lichen Flora of the Greater Sonoran Desert Region. 2, 643–644.
Lumbsch HT, Huhndorf SM. 2007 – Outline of Ascomycota—2007. Myconet 13, 1–58.
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 8 July 2026