Cytospora piceae X. L. Fan

Cytospora piceae X. L. Fan, in Pan, Zhu, Tian, Alvarez & Fan, Phytotaxa 383 (2): 188 (2018) Fig. 3 Description. Sexual morph: not observed. Asexual morph: Conidiomata pycnidial, immersed in bark, erumpent, ostiolated, with multiple irregularly arranged circular or ovoid locules, 1,050 –1,400 μm in diam. Conceptacle absent, ostiole conspicuous, circular, dark gray, at the same level as the disc. Conidiophores semimacronematous, hyaline, filamentous, mainly unbranched or branched at base, elongated, smooth, thin-walled, (16.0 –) 17.7–22.2 (– 23.5) μm. Conidiogenous cells enteroblastic, polyphialidic. Conidia abundant, single, hyaline, aseptate, curved, allantoid, thin-walled (5.0 –) 5.4–6.1 (– 6.5) × (1.0 –) 1.2–1.5 μm. Culture characteristics. Colonies on MEA initially white, becoming beige with dense aerial mycelium, slow-growing (17 mm in diameter) after 7 days of incubation. Hyphae hyaline, smooth, branched, and septate. Material examined. Canada • Ontario, Lincoln, 43°06'38.2"N, 79°19'17.5"W, branches of Picea glauca (Moench) Voss, pycnidia (conidiomata) formed on cankered branches and twigs, April 2020, E. Ilyukhin (BILAS 51883, DAOM 985023, DAOMC 256987). Notes. Morphologically, two isolates of C. piceae are very similar, but EI-19 (A) has slightly longer conidiophores and conidia than CFCC 52841. Originally, C. piceae was described as a pathogen associated with the canker disease of Picea crassifolia in China (Pan et al. 2018). But the species was isolated from different hosts (including non-conifers) in other parts of Canada based on ITS sequence data (ON 352565, PQ 671332, PQ 671333, PQ 666762) available in GenBank.