Aurantiosacculus Dyko & B. Sutton, in Dyko, Sutton & Roquebert, Mycologia (1979)
Sordariomycetes, Sordariomycetidae, Diaporthales, Cryphonectriaceae
Saprobic or parasitic on the host plant in terrestrial habitat. Sexual morph: see Jiang et al. (2019). Asexual morph: Conidiomata bright orange to black, stromatic, pycnidial, solitary to gregarious, intraepidermal, immersed to erumpent, globose and flattened in outline, broadly conical to crateriform in section view, unilocular, glabrous, gelatinous. Ostiole absent, dehiscence by breakdown of the apical wall. Conidiomatal wall composed of thin-walled, hyaline to pale brown cells of textura angularis in the basal wall, becoming thick-walled, gelatinized cells of textura oblita in the upper wall. Conidiophores arising from the inner wall layer of conidiomata, hyaline, cylindrical to subcylindrical, branched, septate, smooth-walled, invested in mucus. Conidiogenous cells hyaline, enteroblastic, several times or with minute periclinal thickening and collarette at the apex. Conidia hyaline, scolecosporous, sigmoid to falcate, tapered at the apex, slightly swollen and bearing a thick truncate scar at the base, unicellular, smooth-walled (Dyko et al. 1979; Nag Raj and DiCosmo 1980)
Type species: Aurantiosacculus eucalypti (Cooke & Massee) Dyko & B. Sutton, in Dyko, Sutton & Roquebert, Mycologia 71(5): 922 (1979)
Notes: Aurantiosacculus was proposed by Dyko et al. (1979) to accommodate a species separated from Protostegia as A. eucalypti, a fungus collected from leaves of Eucalyptus incrassata (Myrtaceae) in Australia. The genus is characterized by bright orange conidiomata and scolecosporous conidia with swollen bases. The conidiogenous cells of Aurantiosacculus eucalypti were described as phialides with several percurrently proliferating towards apex by Dyko et al. (1979) and Nag Raj and DiCosmo (1980). Three additional taxa, A. acutatus Crous & Summerell on E. viminalis and A. eucalyptorum Crous & C. Mohammed on E. globulus, and A. castaneae C.M. Tian & N. Jiang on Castanea mollissima are included (Crous et al. 2012a; Jiang et al. 2019). Aurantiosacculus was placed in Cryphonectriaceae based on the sequence of LSU and ITS (Crous et al. 2012a). More collections of Aurantiosacculus are needed, and an epitype of the generic type is also needed to confirm its placement.
Distribution: Australia, China, Tasmania (Crous et al. 2012a; Jiang et al. 2019). lageniform to subcylindrical, integrated, indeterminate, smooth-walled, with percurrent proliferation.
Aurantiosacculus eucalypti (redrawn from Nag Raj and DiCosmo 1980) a Vertical section of conidioma. b Conidiophores, conidiogenous cells and developing conidia.
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.