Fungalpedia – Note 679, Cycloschizon
Cycloschizon Henn.
Citation when using this data: D. S. Marasinghe et al. 2023 (in prep.) – Fungalpedia, Ascomycota.
Index Fungorum, Facesoffungi, MycoBank, GenBank., Fig. 1.
Classification: Parmulariaceae, Asterinales, Dothideomycetidae, Dothideomycetes, Pezizomycotina, Ascomycota, Fungi
Epiphytic on leaves. Superficial mycelia indistinct. Sexual morph: Ascostroma confluent to gregarious, superficial, orbicular, dimidiate, membraneous to carbonaceous, dark brown to black with circular margins, pulvinate, papillate, opening by one circumferential. Hypostroma developing through living tissue, uniloculate, locules open with an ostiole, developing on the cuticle. Internal stroma lacking or with filiform, septate, dripped, hyaline pseudopara-physes. Asci 8-spored, bitunicate, hyaline to olivaceous brown, ovoid, sessile or short pedicellate. Ascospores 2-celled, clavate to ellipsoidal, hyaline to pale brown, 1-septum, slightly constricted at the septum. Asexual morph: Undetermined.
Notes: Hennings (1902) introduced Cycloschizon with the type species of Cycloschizon brachylaenae which was previously introduced as Schneepia brachylaenae. It was initially placed in Hysteriaceae due to its annular rupture of ascostroma. Inácio and Cannon (2008) compared 12 taxa based on hosts, distributions and main morphological characters. Cycloschizon is characterized by having blackened, circular, flattened, pulvinate, ascomata, producing broadly clavate to subglobose, thick-walled asci and 1-septum, ellipsoidal ascospores (Narendra and Rao 1974; Inácio and Cannon 2008).
Type species: : Cycloschizon brachylaenae (Rehm) Henn., Bot. Jb. 33(1): 39 (1902) [1904]
Other accepted species: species Fungorum – search Cycloschizon.
Figure 1 – Cycloschizon alyxiae. a Leaf specimen. b, c Colonies on the surface of the leaf. d Upper wall of the thyriothecia. e Section through thyriothecia. f Ascospore. Redrawn from Arnaud (1918)
References
Arnaud G 1918 – Les Astérinées. Annales de l’école Nationale d’agriculture de Montpellier 16:1.
Hennings PC 1902 – Fungi S. Paulenses I. a cl. Puttemans Collecti. Hedwigia 41:104–118.
Inácio CA, Cannon PF 2008 – The genera of the Parmulariaceae. CBS biodiversity series, vol 8. CBS Fungal Biodiversity Centre, Utrecht.
Narendra DV, Rao VG 1974 – Some interesting Ascomycetes from India. Sydowia 28:353.
Entry by
Diana Sandamali Marasinghe, Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, 57100, Thailand School of Science, Mae Fah Luang University, Chiang Rai, 57100, Thailand, Mushroom Research Foundation, 128 M.3 Ban Pa Deng T. Pa Pae, A. Mae Taeng, Chiang Mai, 50150, Thailand
Published online 29 August 2023