Graphis mikuraensis Y. Ohmura & M. Nakan., in Ohmura et al., Bull. natn. Mus. Nat. Sci., Taiwan 42(1): 5 (2016)

Index Fungorum number: IF 815136; Mycobank number: MB 815136; Facesoffungi number: FoF 16052; Fig. 1

=Graphis srilankensis Weerakoon et al., Bryologist 115: 79 (2012)

Thallus crustose, corticate, surface smooth, continuous to sometimes cracked, greenish grey to pale yellowish buff. Ascocarp lirellae, erumpent to prominent, long, simple to sparsely branched, with a lateral thick thalline margin, edge round, 0.5–14×0.2–0.3 mm. Disc not visible from the surface. Labia smooth, black, not pruinose. Exciple convergent, entire, completely carbonized. Epithecium indistinct. Hymenium hyaline, inspersed with small oil-droplets persistent in KOH, KI–, 110–155 μm high. Subhymenium hyaline, 10–15 μm high. Ascospores 8 per ascus, hyaline, ellipsoid to sub-fusiform, transversely 11–14 septate, first surrounded by a halo, I+violet, 40–60×6–10 μm.

Secondary chemistry – Norstictic acid major and Salazinic acid minor detected by TLC; K + yellow turns red with cryastals.

Material examined – India, Kerala, Munnar (10° 05′ 24″ N, 77° 03′ 17″ E,+1477 msl.), 18 December 2022, P. A. Ansil and K. C. Rajeshkumar, (AMH22.233).

GenBank numbers – AMH22.233: mtSSU = OR807879, LSU=OR807873, rpb2=OR806897.

Notes – This study reports Graphis mikuraensis as a new record to India and its phylogenetic placement. The sample under the study slightly varies from G. mikuraensis holotype with respect to lirella length and degree of branching. However, we are not considering this single variation enough to propose a new species and identify the species as G. mikuraensis. This sample resembles G. sapii which has elongate and irregularly branched lirellae and by ascospore characters (40–44 × 6–7 μm in length, 12 locules in Zahlbruckner (1930: 40). However, G. sapii differs from our sample in having a scabrous ‘deserpensemorph’ (Lücking 2009; Lücking et al. 2009) lirellae with narrow acute edge, rimiform disc and sometimes sub granulose-uneven thallus. We have also noted the similarity of our sample with Graphis rajapakshana. However, on comparative analysis of G. rajapakshana with G. mikuraensis (syn.: G. srilankensis Weerakoon et al. (2019). The characters (prominent lirellae and ascospore size 35–50 × 7–8 µm) quoted to separate G. rajapakshana from G. mikuraensis were found overlapping with the G. mikuraensis holotype characters (sessile to erumpent lirellae and ascospore size (35–)43.7±5.7(–54) × (6.7–)8.1±0.8(–10) µm). Hence, we suggest synonymizing G. rajapakshana under Graphis mikuraensis Y. Ohmura & M. Nakan. (syn.: G. srilankensis Weerakoon et al. (2019). The phylogenetic analyses using combined mtSSU and LSU sequences placed in G. mikuraensis allied to the clade containing G. leptoclada, G. gracilescensis, G. lineola, G. librata.

Figure 1 – Graphis mikuraensis (AMH22.233). a, b Thallus. c Cross section of lirellae. d Inspersed hymenium. e Paraphyses. f Ascus showing ascospores. g I+ascospore. h–j Ascospores. Scale bars: a=1 mm, b=200 µm, c=50 µm, d–j=10 µm