Graphidaceae of Central French Guiana

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Graphis § Fissurina sp. Harris 33702

Thallus corticolous, thin, epi- to endo?-phloeodal, olivaceous to sordid green, irregularly verruculose-rugose, cartilaginous and waxy-textured with large ± discrete but irregularly puffed, generally elongate white-to-yellowish mottled pseudostromata, often up to 1 cm long by ca. 2 mm wide, with juvenile areas of pseudostroma eggyolk yellow, centrally thicker and white, all covered with thin cartilaginous but not flaking cortex, margins irregularly lobed and elongated but discrete from thallus, continuous to slightly cracked, 0.09 - 0.1 mm thick; cortical layer cartilaginous of short round ended interwoven hyphae, thin; crystal inclusions common in medulla, indicated by verruculae at surface. Ascocarps aggregated in weakly and irregularly raised white to yellow puffed pseudostromata, appearing as narrow, barely gaping (to 0.2 mm) fissures, 0.3-0.4 mm long, with puffed margins immersed in pseudostroma, slightly curved to undulate, unbranched ( 0.04 mm wide). Exciple thin and more or less yellowish laterally with included bark remnants, moderately well-differentiated, hymenium more or less rounded-triangular in cross section, not inspersed, labia converging. Spores 8/ascus, 4-locular, 5x15-18µ, I+ blue, thick-walled with lens-shaped lumina. No lichen substances.

Also examined: H 33931 not as well developed puffing.