Fungalpedia – Note 2529, Chaetoscutula
Chaetoscutula. E. Müll.
Citation when using this data: Boonmee S et al. 2021 – Fungalpedia.
Index Fungorum, Facesoffungi, MycoBank, GenBank, Fig 1
Classification: Incertae sedis, Incertae sedis, Incertae sedis, Dothideomycetes, Pezizomycotina, Ascomycota, Fungi
Notes: Chaetoscutula is a monotypic genus based on Chaetoscutula juniperi E. Mull (Müller 1958). It grows on Juniperus spp. (Cupressaceae) and, although the mycelium is usually inconspicuous, this fungus produces tiny black hemispherical ascomata, solitary or gregarious, between adjacent leaves of the plant. The absence of signs of damage to the host suggests that the species is saprobic. The ascomata surface is characterized by displaying more or less dense, long and gnarled setae. Asci are bitunicate, 8-spored, and spores are cylindrical to clavate, two-celled, at first hyaline and then slightly brownish when mature. The genus was formerly placed within Schizothyriaceae, and later in Saccardiaceae (Müller and von Arx 1962; von Arx and Müller 1975) based on morphological comparisons. Recently, Tian et al. (2014) transferred Chaetoscutula to Pseudoperisporiaceae on the basis of the anatomical similarities to species in Pododimeria, a genus included in that family that also grows on Juniperus leaves (Müller 1958).
Type species: Chaetoscutula juniperi E. Müll., Sydowia 12(1-6): 191 (1959) [1958].
Other accepted species: Species Fungorum – search Chaetoscutula.
Figure 1 – Chaetoscutula juniperi (MA-90552, new record). a–d Ascomata on leaves of Juniperus phoenicea. e, f Ascomata immersed in water showing their hemispherical shape and their surface with dense, long and gnarled setae. g Peridium cells in surface view. h, n, o Setae.
i, j, p Asci in several developmental stages. k–m, q, r Ascospores in several developmental stages. Scale bars: a– d = 0.5 mm, e, f = 50 μm, g–r = 10 μm.
References
Müller E 1958 – Über zwei neue Ascomyceten auf Juniperus-Arten. Sydowia 12:189–196.
Entry by
Saranyaphat Boonmee, 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
Published online 9 June 2026