Arthrinium pseudoparenchymaticum M. Wang & L. Cai

Wang, Mei, Tan, Xiao-Ming, Liu, Fang & Cai, Lei, 2018, Eight new Arthrinium species from China, MycoKeys 34, pp. 1-24 : 8

Arthrinium pseudoparenchymaticum M. Wang & L. Cai sp. nov. Figure 9

Type.

CHINA, Guangdong Province, on bamboo, Jul. 2016, D.W. Xiao, (holotype: HMAS 247189; culture ex-type: CGMCC 3.18336 = LC7234).

Etymology.

Referring to the pseudoparenchymatous hyphae.

Description.

Hyphae hyaline to pale brown, branched, septate, 1.5-5.0 μm diam., pseudoparenchymatous. Conidiophores aggregated in hyaline to light brown sporodochia, smooth, usually unbranched, up to 40 μm long, 3-6 μm width. Conidiogenous cells hyaline to pale yellow, smooth to finely roughened, subcylindrical to doliiform, 8.0-18.5 × 3.0-8.5μm (x̄ = 13.7 ± 3.2 × 5.4 ± 1.2, n = 30). Conidia pale to dark brown, smooth, finely guttulate, globose to subglobose, 13.5-27.0 × 12.0-23.5 μm (x̄ = 20.2 ± 2.5 × 17.1 ± 2.4, n = 50). Sometimes lobed or dentate, polygonal or irregular in surface view.

Culture characteristics.

On PDA, colonies flat, spreading, margin circular, with moderate aerial mycelia, initially white, becoming grey on surface, reverse smoke-grey without patches, reaching 9 cm in 8 days at 25 °C. On MEA, surface pale luteous to grey with abundant mycelia, reverse greyish without patches.

Other specimens examined.

CHINA, Guangdong Province, on bamboo, Jul. 2016, D.W. Xiao, living culture LC8173; ibid. living culture LC8174.

Notes.

Arthrinium pseudoparenchymaticum is closely related to A. hyphopodii (94% sequence similarity in ITS), but differs in its much larger conidia (13.5-27.0 × 12.0-23.5 μm vs. 5-10 × 4-8 μm), the absence of hyphopodia and the presence of dentate conidia.