Leptoparies magnoliae N.I. de Silva & S. Lumyong, sp. nov.
MycoBank number: MB; Index Fungorum number: IF; Facesoffungi number: FoF 12709, Fig. *
Etymology: Name reflects the host genus Magnolia, from which the new species was isolated.
Holotype: MFLU 18-1291
Saprobic on dead twigs attached to Magnolia sp. Sexual morph: Ascomata 240–290 µm high × 230–270 µm diam., ( = 265 × 250 µm, n = 10), dark brown to black, solitary or scattered, unilocular, immersed to slightly erumpent, subglobose, ostiolate. Ostiolar neck 60–90 µm high × 200–230 µm wide, crest-like, elongated, laterally compressed, composed of globose, brown to black cells, with hyaline periphyses. Peridium 15–25 µm wide, composed several layers of small, brown to dark brown, thin-walled, cells of textura angularis, fusing and indistinguishable from the host tissues. Hamathecium comprising 1–2 μm wide, numerous, filamentous, indistinct septate, cellular pseudoparaphyses, anastomosing at the apex. Asci 40–65 × 8–11 µm ( = 58 × 9 µm, n = 20), 8-spored, bitunicate, fissitunicate, cylindrical-clavate, short pedicellate, apically rounded with an ocular chamber. Ascospores 15–19 × 4–6 µm ( = 16 × 5 µm, n = 30) without sheath, overlapping, uni to bi-seriate, hyaline, fusiform with obtuse ends, slightly constricted at the septum, smooth, guttulate, generally 4 guttules, with a narrow sheath. Sheath drawn out 4–6 μm long at both ends, with a lateral pad, 1–1.5 μm wide at side. Asexual morph: Undetermined.
Material examined: Thailand, Chiang Mai Province, on dead twigs attached to Magnolia sp. (Magnoliaceae), 13 September 2017, N. I. de Silva, NI189 (MFLU 18-1291, holotype).
Notes: According to the multi-gene phylogeny, Leptoparies magnoliae clustered with L. palmarum with 100% ML and 1.00 BYPP support (Fig. 2). Leptoparies magnoliae can be distinguished from L. palmarum in having smaller asci and ascospores. Leptoparies magnoliae is characterized by the smaller asci (58 × 9 µm) and ascospores (16 × 5 µm) whereas L. palmarum is characterized by larger asci (93.9 × 11.9 μm) and ascospores (23.1 × 6.1 μm) . Ascomata of L. magnoliae is smaller (240–290 µm high × 230–270 µm diameter) than L. palmarum (210–320 μm high and 490–650 μm diameter) . Peridium of L. magnoliae is thinner 15–25 µm wide, comprising several layers of cells compared to L. palmarum which is 25–32 μm wide, comprising 3-5 layers of cells . A pairwise comparison of ITS sequence data between L. magnoliae and L. palmarum indicates 16 base pair (3.2%) differences across 500 nucleotides. It is interesting to note that L. magnoliae is the second species recorded for Leptoparies. The first species, L. palmarum was identified by Hashimoto et al.  on petioles of Trachycarpus fortunei (Arecaceae) in Japan.
Figure *. Leptoparies magnoliae (MFLU 18-1291, holotype). (a) The specimen. (b, c) Appearance of ascomata on the host substrate. (d, e) Vertical sections through ascoma. (f) Peridium. (g, h) Pseudoparaphyses and asci. (i) Ascus. (j–m) Ascospores. Scale bars: (a) = 500 μm, (b, c) = 200 μm, (d, e) = 50 µm, (g–i) = 10 µm, (f, j–m) = 5 µm.