Tracylla (Sacc.) Tassi, Bulletin Labor. Orto Bot. de R. Univ. Siena 6: 62 (1904) non Tracyella Zambet-takis (nom. illegit.) in Rev. Mycol. 35: 165. (1970)
Sordariomycetes, Incertae sedis, Tracyllalales, Tracyllaceae
Saprobic on the host plant in terrestrial habit. Sexual morph: undetermined. Asexual morph: Conidiomata brown to dark brown, pycnothyrial, solitary to gregarious and confluent, superficial, orbicular to oval or irregular in outline, connected to the immersed mycelium by a central supporting column of cells. Conidiomatal wall composed of thick-walled cells of textura angularis in the centeral zone, becoming thinner-walled cells of textura prismatica at the peripheral zone with radially elongated cells that are entire or invaginated at the edge. Conidiophores arising from the inner wall layer of upper pycnothyrial shield and the central column of supporting cells, reduced to conidiogenous cells, invested in mucus. Conidiogenous cells hyaline to subhyaline, enteroblastic, phialidic, lageniform to cylindrical, determinate, smooth-walled. Conidia hyaline, broadly ellipsoidal to naviculate or lunate, truncate at the base, unicellular, smooth-walled, guttulate, bearing unbranched, attenuated, flexuous appendage at one end or both ends (Nag Raj 1974, 1975, 1993).
Type species: Tracylla spartinae (Peck) Tassi, Bulletin Labor. Orto Bot. de R. Univ. Siena 6: 62 (1904)
Notes: Tracyella (Cif.) Zambett. typified with T. hydrocharidis Zambett. was considered as a nomen dubium (Nag Raj 1975). A detailed revision of Tracylla was made by Nag Raj (1975). Peck (1894) used the binomial Leptothyrium spartinae Peck for a fungus collected on dead stems of Spartina juncea (Poaceae) in the USA. Peck (1894) noted that this species was distinct from other Leptothyrium species in its shield-like conidiomata with radiate structure in the margins and larger conidia with a filiform appendage at each end. Saccardo (1895) subdivided the genus Leptothyrium into the subgenera: Eu-Leptothyrium Sacc. for species with muticate conidia and Tracylla Sacc. for those with conidia bearing an appendage at both ends. Tassi (1904) elevated Tracylla to generic rank with T. spartinae (Peck) Tassi as type species. Another species T. aristata (Cooke) Tassi was also included in Tracylla. Moesz (1914) added three additional taxa, T. andrasovszkyi Moesz, T. julia (Speg.) Moesz and T. minima (Berk. & Curt.) Moesz. Nag Raj (1975, 1993) re-described Tracylla and accepted only two taxa, T. aristata and T. spartinae. Crous et al. (2018a) introduced a new family Tracyllaceae to accommodate Tracylla and added a new species T. eucalypti. The type species of Tracylla has not been studied by molecular data. Fresh collections and cultures are needed to confirm its placement.
Distribution: Australia, Brazil, Jamaica, New Zealand, Philippines, Sri Lanka, Thailand, USA (Nag Raj 1993, Crous et al. 2018a).
Li WJ, McKenZie EHC, Liu JK, Bhat DJ, Dai DQ, Caporesi E, Tian Q, Maharachcikumbura SSN, Luo ZL, Shang QJ, Zhang JF, Tangthirasunun N, Karunarathna SC, Xu JC, Hyde KD (2020) Taxonomy and phylogeny of hyaline-spored coelomycetes. Fungal Diversity 100: pages279–801.