Graphis andamanica Swarnal., 2017

Swarnalatha, G., 2017, A new species of Graphis (Graphidaceae) from India, Phytotaxa 313 (1), pp. 144-146 : 144-146

Graphis andamanica Swarnal. , sp. nov. ( Fig. 1A‒D )

Mycobank#821830

Differs from Graphis gloriosensis A.W. Archer & Elix in the longer and more prominent lirellae; the lateral to basal thalline margin and the cinnamon red hymenial inspersion.

Type: — INDIA. Andaman islands, South Andaman, Wright Myo, alt. c. 30 m, 18 April 1961, A. Singh 88290 (holotype LWG!).

Thallus crustose, corticolous, epiperidermal; surface yellowish-white, shiny, finely to deeply cracked; thallus in section ecorticate, 40–130 μm thick above the bark, with clusters of calcium-oxalate crystals. Photobiont green, a species of Trentepohlia . Ascomata lirellate, prominent, black, simple to often radiately to dendroidly branched, curved or flexuous, (1.3–) 5–15 mm long, 0.1–0.25 mm broad, acute to rounded at the end; disc closed, epruinose; excipulum completely carbonized, covered by a lateral to basal thalline margin with abundant calcium-oxalate crystals; labia convergent, entire; hymenium inspersed with cinnamon red, irregular, dense granules, completely obstructing the view of the asci and ascospores, dissolving in KOH without any colour reaction, 95–110 μm high, I –; epihymenium dark brown, 6–10 μm thick, K –; subhymenium hyaline 18–26 μm thick; paraphyses simple to branched, tips branched with brown walled. Asci clavate, 95–110 × 18–27 μm. Ascospores 8 per ascus, sub-biseriate to biseriate or aggregrate, ellipsoid, sometimes narrow at the lower end, transversely septate, 48–60 × 7–9.6 μm, (9–)13–17 locular, hyaline and I + blue violet.

Secondary chemistry:— Thallus K + reddish-brown, P –, UV + pale yellow; stictic and constictic acids (major), orange brown spot (Rf class–2) detected by TLC.

Etymology:— The specific epithet refers to the region where it was collected.

Remarks:— Graphis andamanica can be easily recognised by its prominent, black, much branched, rather long lirellate ascomata, its completely carbonized excipulum covered by basal to lateral thalline margin, its convergent, entire labia, its hymenium inspersed with cinnamon red granules, the hyaline, transversely septate, mid-sized ascospores and presence of stictic and constictic acids.

The new species is very similar to G. gloriosensis in anatomical and chemical aspects, but the latter differs in its shorter (2–4 mm long) lirellae, the thick lateral thalline margin, and the unpigmented hymenial inspersion.

Graphis filiformis , a species already known from India, is similar to G. andamanica in hymenium inspersion with orange brown granules, but G. filiformis differs in the laterally carbonized excipulum, the indistinctly striate labia ( Fig. 2A‒B ), the shorter (21–25 × 6–8 μm) ascospores, and the presence of norstictic acid; it should be noted here that Adawadkar & Makhija (2007) reported as clear hymenium for this taxon.

Figures

FIGURE 1. Graphis andamanica (holotype). A. Thallus with ascomata; B. Cross section of ascomata; C. Paraphyses with inspersion granules; D. Ascospores. Scales = 1 mm in A; 50 μm in B; 10 μm in C‒D.

FIGURE 2. Graphis filiformis (holotype). A. Thallus with ascomata; B. Cross section of ascomata. Scale = 1 mm A; 50 μm in B.