Nigrospora osmanthi Mei Wang & L. Cai

Nigrospora osmanthi Mei Wang & L. Cai View in CoL , Persoonia 39: 135 (2017)

Fig. 15 View Figure 15

Description.

Sexual morph: Not observed. Asexual morph: Hyphae interwoven, initially hyaline, becoming pale brown to yellowish-brown with age, thick-walled, septate, frequently branched, 2.0–5.1 µm diam. Conidiophores reduced to conidiogenous cells. Conidiogenous cells solitary on hyphae, smooth-walled, hyaline turning pale yellowish-brown with maturation, variable in shape (phialidic, short-clavate, subglobose to cylindrical), 7.8–13.7 × 4.1–7.8 µm (av. ± S. D. = 8.2 ± 3.0 × 5.5 ± 1.1). Conidia solitary, initially hyaline, maturing to black, smooth-walled, aseptate, subglobose, 12.0–15.2 × 7.9–14.4 µm (av. ± S. D. = 13.5 ± 0.8 × 11.7 ± 1.3).

Cultural characteristics.

On PDA medium, colonies initially appeared white and cottony with abundant aerial mycelium, spreading radially to form concentric rings. Three distinct pigmentation zones were observed from the surface view, exhibiting a darker central region. At 10 days, the central zone developed a smoke-gray coloration while the margins gradually faded to whitish-gray. By 20 days, the entire colony turned uniformly grayish-black, maintaining a cottony, appressed growth habit across the agar surface.

Specimens examined.

China • Beijing City, Changping District, Dingling Scenic Area, Ming Tombs , 40°17'28"N, 116°14'31"E, on the healthy strobili of Juniperus chinensis , 31 March 2025, Z. X. Bi, BJFC -S 2577 , living culture CFCC 72646 GoogleMaps ; China • Beijing City, Changping District, Dayu Mountain Scenic Area, Ming Tombs , 40°18'20"N, 116°12'4"E, on the diseased scale leaves with lesions of Platycladus orientalis , 23 October 2024, Z. X. Bi & M. H. W, BJFC -S 2576 , living culture CFCC 72649 GoogleMaps .

Notes.

Nigrospora osmanthi was first described by Wang et al. (2017) based on specimens isolated from Osmanthus sp. Subsequent studies have documented its occurrence on diverse host plants, including Cirsium setosum , Codium sp. , Fagopyrum tataricum , Phyllostachys nigra , Phragmites australis , Rosa chinensis , Rudbeckia hirta , and Ulva sp. ( Hao et al. 2020; Shen et al. 2021; Lee et al. 2023). Based on comprehensive phylogenetic and morphological analyses, strains CFCC 72646 and CFCC 72649 were identified as N. osmanthi .