Tympanis spermatiospora (Nyl.) Nyl., Not. Sällsk. Fauna et Fl. Fenn. Förh., Ny Ser. 10: 70 (1868) 
= Sirodothis populi Clem., Gen. fung. (Minneapolis): 176 (1909)
= Sirodothis populnea (Thüm.) B. Sutton & A. Funk, Can. J. Bot. 53(6): 524 (1975)
Habit on Populus tremuloides and Populus spp. (Salicaceae). Sexual morph: see Groves (1952). Asexual morph: Conidiomata dark brown to black, stromatic, caulicolous, immersed to erumpent, consisting of one to several caespitose, globose, unilocular, pycnidium-like structures arising from a common basal stroma, glabrous or pruinose. Ostiole absent, dehiscence by irregular splits of the apical wall. Conidiomatal wall composed of thick-walled, brown to dark brown cells of textura angularis, becoming darker, thicker, sclerotioid toward the margin. Conidiophores arising from the inner layer cells of the locular wall, hyaline, filiform, branched mostly at the base, septate, smooth-walled. Conidiogenous cells hyaline, enteroblastic, phialidic, cylindrical to subcylindrical, integrated or discrete, determinate, smooth-walled, terminal or lateral, apertures arising immediately below transverse septa, with periclinal thickenings wall at collarette region. Conidia hyaline, cylindrical, unicellular, smooth-walled (Nag Raj 1977, Sutton 1980).
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.