Apiospora ulmicola Ning Jiang, sp. nov. (Fig. 2)

MycoBank 853729

Etymology:— Named after the host genus Ulmus, and -cola = inhabiting.

Original descriptions:— Hyphae 1.5–5.5 μm diam., hyaline, branched, septate. Conidiophores hyaline to pale brown, mononematous, transversely septate, thick-walled, 8.5–56 × 1.5–5 μm, arising from long, ampulliform conidiophore mother cells. Conidiophore mother cells borne directly on hyphae are hyaline, smooth, lageniform, 1.5–9.5 × 2–4.5 μm. Conidiogenous cells hyaline, smooth, subglobose, 1.5–4.5 μm diam. Conidia borne as bunches on conidiophores, lateral and terminal, brown, smooth, aseptate, globose in surface view, lenticular in side view, with pale equatorial slit, 2.5–4 μm diam in surface view, 2–3.5 μm diam in side view, with a central scar.

Culture characteristics:— Cultures on PDA white, flocculent, spreading, fast growing, up to 9 cm diam after 5 days at 25 °C. Cultures on MEA initially white, flocculent, spreading, fast-growing, growing up to 9 cm after 5 days at 25 °C, becoming fawn after 10 days.

Materials examined:— CHINA. Beijing, Haidian District, Qinglongqiao Street, 40°0’14”N, 116°14’23”E, on a healthy leaf of Ulmus pumila, Ning Jiang & Xiaoye Yin, 16 May 2022, holotype CAF800089; ex-type culture CFCC 57941; Ibid. (culture CFCC 57942).

Notes:— Two isolates of Apiospora from healthy leaves of Ulmus pumila clustered into a well-supported clade distinguished from the other members within this genus (Fig. 1). Phylogenetically, the new species, Ap. ulmicola is close to Ap. intestini (Kajale, Sonawane & Roh. Sharma) Pintos & P. Alvarado, originally published as Arthrinium gutiae Kajale, Sonawane & Roh. Sharma, from the gut of a grasshopper in India (Fig. 1). However, Ap. ulmicola is distinguished from Ap. intestini by smaller conidia in surface view (2.5–4 μm diam in Ap. ulmicola vs. 4.5–6 μm diam in Ap. intestini; Crous et al. 2015). In addition, Ap. ulmicola differs from Ap. intestini in nucleotide sequence data (5/ 537 in ITS, 3/ 338 in tef1).