Arecophila xishuangbannaensis L.S. Han & D.Q. Dai sp. nov.

Fig. 3

Etymology.

Named after the location “Xishuangbanna” where the new taxon was discovered.

Holotype.

GMB-W1283.

Description.

Saprobic on dead culms of bamboo. Sexual morph: Ascomata 540-700 × 320-450 µm (x- = 586 × 389 µm, n = 20), immersed beneath a black clypeus, forming white ring surrounding ostioles of ascomata, solitary or scattered, sometimes gregarious, globose to subglobose, dark brown to black. Ostioles papillate, central, black. Peridium 15-25 µm thick, comprised of several layers, thick-walled, dense, brown to hyaline, cells of textura angularis. Paraphyses 2.5-6 μm wide, hyaline, numerous, cylindrical, unbranched, septate. Asci 180-270 × 12-14 μm (x- = 213 × 12.8 μm, n = 20), 8-spored, unitunicate, cylindrical, pedicellate, straight or slightly curved, apically rounded, with a 3.7-4.7 μm wide, 2.5-3 μm high (x- = 4.3 × 2.7 μm, n = 20), wedge-shaped, J+, apical ring. Ascospores 23-27 × 8.5-9.5 μm (x- = 24.5 × 8.8 μm, n = 20), overlapping, uniseriate, initially hyaline, pale brown to dark brown when mature, ellipsoidal, medianly 1-septate, tapering towards both ends, slightly constricted at the septum, with longitudinal striation along entire length of the ascospore, surrounded by a 3.5-5 µm thick, distinct, globose to subglobose, mucilaginous sheath. Asexual morph: Undetermined.

Materials examined.

China, Yunnan Province, Xishuangbanna, Jinghong, Manzhang, Mengla, 21°91′97"N, 101°20′42"E, 617.14 m, on dead culms of bamboo, 16 August 2020, Dong-Qin Dai, Li-Su Han, DDQ00993, (GMB-W 1283 holotype), ibid. (ZHKU 23-0258, isotype), ibid. DDQ00993-1 (ZHKU 23-0280) .

Notes.

In the phylogenetic tree, our new collections of Arecophila xishuangbannaensis (GMB-W1283, ZHKU 23-0280) formed a well-separated sister branch with A. bambusae (HKUCC 4794) and Arecophila sp. (HKUCC 6487) with 92% ML, 0.94 PP statistical supports (Fig. 1). Based on a nucleotide base pair comparison, A. xishuangbannaensis differs from A. bambusae (HKUCC 4794) in LSU gene (15/736 bp, 2%). Morphologically, A. xishuangbannaensis is similar to A. bambusae, in having cylindrical asci and ellispoidal ascospores. However, our new taxon differs A. bambusae by forming a white ring surrounding ostioles of ascomata and having larger asci (180-270 × 12-14 μm vs. 132.5-140 × 7.5-8 µm) and larger ascospores (23-27 × 8.5-9.5 μm vs. 19-22.5 × 5.5-7 µm) (Umali et al. 1999; Li et al. 2022). Arecophila xishuangbannaensis also resembles A. notabilis K.D. Hyde, but it has larger ascomata (586 × 389 µm vs. 400 × 360 µm) (Hyde 1996). The spores of this species did not germinate on PDA or malt extract agar (MEA) media, thus no culture is available.