Dictyosporium nigroapice Goh, W.H. Ho & K.D. Hyde
Index Fungorum number: IF450470; Facesoffungi number: FoF04683
Etymology: nigroapice, referring to the blackened apical portion of the conidia.
Colonies on natural substratum in the form of compact sporodochia. Sexual morph: Undetermined. Asexual morph: Conidiophores hyaline to pale brown, thin-walled, short, irregularly branched. Conidiogenous cells cylindrical, determinate. Conidia 28–41 × 15–20 µm (x̄ = 33.9 × 17.1 µm, n = 30), complanate, cheiroid, smooth-walled, brown, consisting of 20–32 cells, arranged in 4 rows, with the apical cells of the 2 inner rows dark brown to almost black in colour, and the apical cells of the outer rows being provided with an appendage which is hyaline, thin-walled, cylindrical, measuring 22–34 × 4–5 µm.
Materials examined: CHINA, Hong Kong, Tai Po Kau Forest Stream, on submerged wood bait of Machilus velutina (Lauraceae), 27 Sep. 1996, W.H. Ho and K.M. Tsui (HKU(M) 4856, holotype); ibid., (HKU(M) 4867, 4868); ibid., on submerged wood, 29 Dec. 1996, W.H. Ho and S.Y. Ho (HKU(M) 5922); ibid., 28 Sep. 1997 (HKU(M) 8647); THAILAND, Nakom Ratchasima Province, Khao Yai National Park, Tad Ta Phu, on submerged test block of Anisoptera oblonga (Annonaceae), 11 June 1997, Somsak Sivichai (SS0349).
Notes: Conidia in Dictyosporium nigroapice are characterized by conspicuously darker apical cells of the two inner arms, rarely darker at the apex of the outer arms. Morphological characters of this collection well agree with the original diagnosis of the holotype of D. nigroapice (Goh et al. 1999).
Freshwater distribution: Hong Kong, China (Goh et al. 1999; Sivichai et al. 2002; Yang et al. 2018), Thailand (Goh et al. 1999)
Goh TK, Hyde KD, Ho WH, Yanna (1999) A revision of the genus Dictyosporium, with descriptions of three new species. Fungal Divers 2:65–100
Yang J, Liu JK, Hyde KD, Jones EBG, Liu ZY (2018) New species in Dictyosporium, new combinations in Dictyocheirospora and an updated backbone tree for Dictyosporiaceae. Mycokeys 36:83–105
Sivichai S, Jones EBG, Hywel-Jones NL (2002) Fungal colonisation of wood in a freshwater stream at Tad Ta Phu, Khao Yai National Park, Thailand. Fungal Divers 10:113–129