Graphidaceae of Central French Guiana

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Graphis sp. Buck 25726

Thallus corticolous, epiphloeodal, thin, uniform, continuous, and cracking in age, lacking a distinct prosoplectenchymatous layer, but with a thin clear cortical layer, rough, and irregular, since thallus is slightly and minutely warty, light-yellowish green to grayish, K+ yellow, P-. Apothecia lirelline, short to long and flexuose, 0.5- 2mm and often up to 5 or 10 mm long by 0.2 u wide, sessile, but appearing emergent due to thick, concolorous irregular thalline margin covering all but apices of lirellae, with very thin veil at apex, consequently labia appearing slightly glaucescent, branching common, but not densely so, with much corticate thallus between branches although lirellae sometimes aggregated and subasteriform. Disk not exposed, sometimes labia very slightly open. K+ yellow, P-. Hymenium rounded below, taller than broad, hypohymenium yellowish-brown. Exciple carbonized throughout, entire to very slightly crenate laterally and closed below, carbonized or with dense sooty-brown tissue. Paraphyses simple, rather dense, straight, eseptate, nonbranching, non-clavate. Spores I-, 8/ascus, 6 x 23-29µm, transversely septate 6-8 locules, oblong to tapered at one end. No lichen substances.

Also examined: H 33355, H 34034, B 18356, H 33385, H 33914