Amphisphaeria falcata H. L. Si, R. L. Chang, T. Bose & Y. C. Wang 2025, sp. nov.

Amphisphaeria falcata H. L. Si, R. L. Chang, T. Bose & Y. C. Wang sp. nov. Fig. 5 a – i Etymology. The name refers to the sickle-shaped conidia. Type. China • Yunnan Province, Chuxiong Yi Autonomous Prefecture, Chuxiong City, Dayao County (26°32'71.54"N, 100°57'3.6"E), isolated from the medullary tissue of the lichen Usnea diffracta (SDCX 40), 13 Nov. 2020, H. L. Si, CX 40 A 8 = CGMCC 3.23740 (the ex-holotype culture), dried culture HMAS 352144 (holotype specimen), GenBank Accession Numbers: ITS OQ 645270; LSU OQ 645284; SSU OQ 625477; RPB 2 OQ 696281; and β-tubulin OQ 696283. Description. Hyphae smooth, grey, septate, septa inconspicuous, compartments cylindrical, branched, measuring 1.19-3.15 μm (x ̄ = 1.93 μm, n = 50) in diam (Fig. 5 c – f). Conidia hyaline, surface smooth, sickle-shaped, 25.07-42.22 × 1.12-2.43 μm (x ̄ = 31.83 × 1.76 μm, n = 11) in diameter (Fig. 5 g – i). No sexual morph was observed. Culture characteristics. On PDA, after 10 days of incubation at 25 ° C, the colonies were white in colour, velvety on the surface, slightly raised in the centre, with an entire margin and irregular radial folds (Fig. 5 a), and the reverse was yellow in the centre with a white halo around the margin (Fig. 5 b). The optimum growth temperature was 25 ° C (1.42 mm / day). No growth was detected at 5 ° C and 35 ° C. Host. Usnea diffracta. Distribution. Yunnan, China. Note. Amphisphaeria falcata is phylogenetically close to A. verniciae. However, the sexual state of A. falcata has not been observed, and the conidia of A. verniciae have not been observed. There is a significant variation, a total of 297 bps, in the ITS, LSU, β-tubulin, and RPB 2 gene sequences between these two species (ITS 71 bps, LSU 15 bps, β-tubulin 162 bps, RPB 2 49 bps).