Dicephalospora sessilis
Dicephalospora sessilis Ekanayaka & K.D. Hyde, sp. nov.
Index Fungorum number: IF556289; Facesoffungi number: FoF 05899; Fig. 30.
Etymology – refers to sessile apothecia
Holotype – MFLU 18-1823
Saprobic on dead stems. Sexual morph: Apothecia 0.8–1 × 0.6–1 mm, arising singly, sessile, slightly erumpent. Receptacle cupulate, reddish orange. Margins smooth, magenta to reddish orange. Disc concave, magenta to orange. Ectal excipulum 40–50 µm ( x = 44 µm, n = 10) in upper flanks, composed of thin-walled, yellowish to hyaline cells of textura prismatica to intricata. Medullary excipulum 90–115 µm (x = 102 µm, n = 10) in upper flanks, composed of thin-walled, yellowish to hyaline, gelatinized cells of textura intricata. Hymenium hyaline to yellowish. Paraphyses 1.5–3 µm wide ( x = 1.8 µm, n = 20), numerous, filiform, obtuse, aseptate, exceeding the asci in length, smooth. Asci 130–140 × 15–20 µm (x = 134.4 × 16.3 µm, n = 30) 8-spored, unitunicate, cylindric-clavate, rounded apex, stipitate base, croziers absent. Ascospores 15–20 × 5–10 µm (x = 18.2 × 7 µm, n = 40), 1–2-seriate, ellipsoid to fusoid, pointed ends, sometimes with gelatinous cap, aseptate, hyaline to yellowish, guttulate. Asexual morph: Undetermined.
Material examined – China, Yunnan Province, Kunming, Kunming institute of botany, Botanical Garden, 24 May 2018, A.H. Ekanayaka, HC19 (MFLU 18-1823). GenBank accessions – LSU- MK591974, ITS- MK584947, SSU- MK585047, TEFMK714028, RPB2- MK577779
Notes – Our Chinese collection HC19 grouped sister to Dicephalospora dentata HMAS 266694 with strong statistical support of 83% (Fig. 26). The ITS data of our species is similar to that of Dicephalospora rufocornea (TNS:F-40024) (517/554-93% with 17 gaps). LSU data of our collection shows 97% similarity to that of Dicephalospora rufocornea (TNS:F-40024) (1060/1097-97% with 8 gaps). Dicephalospora sessilis is characterized by having sessile, cupulate, reddish orange apothecia, smooth margins, gelatinous excipulum, filiform paraphyses, cylindric-clavate asci and ellipsoid to fusoid ascospores with pointed ends. Our new species is phylogenetically close to Dicephalospora dentata and D. rufocornea. However, D. dentata differs from D. sessilis by having dentate apothecial margins, longer asci and narrower ascospores and D. rufocornea differs in having stipitate apothecia (Spooner 1987, Liu et al. 2016). Dicephalospora sessilis is similar to D. calochroa, but differs in having smaller asci and ascospores (Spooner 1987).
Figure 26 – Phylogram generated from maximum likelihood analysis of sequences of Helotiaceae
based on ITS and LSU sequence data. MLBP values ≥50% are given near the nodes. Strain/culture
numbers are given after the taxa. The tree is rooted with Chlorociboria cf. aeruginosa (AFTOL-ID
151).
Figure 30 – Morphology of Dicephalospora sessilis (MFLU 18-1823 holotype) a Substrate. b, c
Apothecia on wood. d Cross section of an apothecium at margins. e Filiform paraphyses. f–g
Cylindric-clavate asci. h–k Fusoid ascospores. Scale bars: d = 60 µm, f, g = 25 µm, h–k = 10 µm, e
= 20 µm.
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