Endosporium populi-tremuloides Tsuneda, in Tsuneda, Davey, Hambleton & Currah, Botany 86(9): 1023 (2008) Fig. 1
Index Fungorum number: IF536901; Facesoffungi number: FoF 06239
Pathogenic on bud of Populus tremuloides. Sexual morph: Undetermined. Asexual morph: Colonies (conidiomata) on PDA, OA and CA black, raised, cerebriform, comprising numerous cellular clumps in a thin glop covering, subcircular to irregular in outline, reverse black. Margin irregular with scarce, occasionally aggregated hyphae on PDA, even with appressed or submerged hyphae on MEA. On PDA, conidiogeneous cells 6–15 µm × 8–20 µm (x̅ = 11.5 × 19.8 µm, n = 10), broad, subhyaline and dumbbell-shaped when two-celled, later splitting by septations in all directions, turning darkly pigmented, irregular in shape, frequently separating into smaller clumps. Hyphae 65 µm long, 3–6 µm wide cylindric-shaped or torulose, light to dark brown, branched or unbranched, aerial ones determinate in growth, mostly elongated, hyaline at the apex, forming muriform and darkly pigmented bodies. Endoconidia 2.5–5 µm × 1–3 µm (x̅ = 3.5 × 2.8 µm, n = 10), developing from the separation of adjacent daughter cells in cellular clumps through schizolytic septum, unicellular, hyaline, ellipsoidal to subglobose turning broadly ellipsoidal to globose. Blastic conidia 2.5–14.5 µm × 1–4.5 µm (x̅ = 3.5 × 2.8 µm, n = 10), abundant in mature colonies, arising from cells of cellular clumps or rarely from sides of hyphae, unicellular, hyaline or light brown, cylindrical to ellipsoidal, regularly truncate at the base, sometimes ovoid.
Material examined – CANADA, Whitemud Creek, Edmonton, Lansdowne, ca. 1 km west of the Northern Forestry Centre, Alberta, on bud of Populus tremuloides (Salicaceae), 3 November 2002, A. Tsuneda (UAMH 10529, holotype).
Economic significance – Species of the genus Endosporium are phytopathogenic fungi that cause scab, anthracnose, and leaf spot diseases on woody plants, as well as species of Salicaceae (Taylor et al. 2001, Butin & Kehr 2004). The genus Endosporium can also cause mycotic diseases in humans due to their meristematic growth (Tsuneda et al. 2008).