Fungalpedia – Note 628, Caudella
Caudella Syd. & P. Syd.
Citation when using this data: D. S. Marasinghe et al. 2023 (in prep.) – Fungalpedia, Ascomycota.
Index Fungorum, Facesoffungi, MycoBank, GenBank.
Classification: Microthyriaceae, Microthyriales, Incertae sedis, Dothideomycetes, Pezizomycotina, Ascomycota, Fungi
Epiphytic and biotrophic on leaf surfaces appearing as small black spots. Hypostroma lacking. Superficial mycelium composed of dark brown or brown, branched, appressoriate hyphae. Appressoria few, unicellular, brown, lateral, globose or sometimes irregularly lobed. Sexual morph: Thyriothecia circular, dark brown to black, gregarious to scattered, sub carbonaceous, poorly developed basal layer with a central irregular pore. Upper wall composed of tightly arranged which are branching from the central pore to the outside. Peridium comprising of compacted black-brown cells of textura angularis. Hamathecium with hyaline, cellular, septate branched, pseudoparaphyses. Asci 8-spored, overlapping 2–3-seriate, bitunicate, fissitunicate, cylindrical clavate short- pedicellate without distinct ocular chamber. Ascospores clavate or ovate-ellipsoid, hyaline, 1-septum, medium septate, upper cell slightly larger than lower cell, narrow and tapering, sometimes bearing bipolar bifurcate appendages, smooth-walled. Asexual morph: Undetermined (Pereira and Filardi 2006; Wu et al. 2011a).
Notes: Caudella was introduced by Sydow and Sydow (1916) with the type species C. oligotricha collected from Flacourtiaceae species in the Brazilian Amazon (Sydow and Sydow 1916). It is characterized mainly by caudate, hyaline ascospores, vesicular haustoria, superficial hyphae with lateral appressoria and the lack of a hypostromata. Caudella is similar to Asterina by its orbicular thyriothecia with appressorial superficial hyphae, however the upper wall of Caudella comprises of irregular lobed cells and it has hyaline ascospores with tapering lower cells or bearing bipolar bifurcate appendages (Fig.1). Pereira and Filardi (2006) also observed vesicular haustoria in C. bipolaris which was collected from the leaves of Bredemeyera floribunda in Brazil. Müller and von Arx (1962) placed this genus in Microthyriaceae based on its orbicular thyriothecia, cylindrical asci with caudate, hyaline ascospores. Wu et al. (2011a) re-examined the type species of C. oligotricha and suggested to place this genus in Micropeltidaceae based on the cell arrangement of upper wall of thyriothecia. Hongsanan et al. (2020a) placed Caudella in Asterinales genera incertae sedis based on the orbicular thyriothecia, appressoriate hyphae with vesicular haustoria and it needs molecular data to confirm its phylogenetic placement.
Type species: Caudella oligotricha Syd. & P. Syd., Annls mycol. 14(1/2): 90 (1916).
Other accepted species: Species Fungorum – search Caudella.
Figure 1 – Caudella bipolaris (VIC 29371). a Colonies on the leaf surface. b Hyphae with appressoria. c Ascus. d Ascospores. e Ascospores of Caudella oligotricha. Scale bars: b–d = 10 μm. Redrawn from Pereira and Filardi (2006) and Wu et al. (2011a)
References
Müller E, von Arx JA 1962 – Beitr Kryptogamenfl Schweiz 11:1–922.
Sydow H, Sydow P 1916 – Fungi amazonici a cl. E. Ule lecti. Ann Mycologici 14:65–97.
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