Graphidaceae of Central French Guiana

---

Graphis cf. grammatis B 25349

Thallus extensive, pale, slightly greyish-metallic green, thick, prosoplectenchymatous, crustose, corticolous, completely covered by apothecia, and cracked throughout, K+ yellow, P+ orange. Apothecia long lirelline, 1-5 mm long by ca. 0.2 mm wide, disk exposed about 0.1mm, reddish brown, mostly unbranched to once branched, margins creamy white and slightly raised, generally straight to quite curved,overall appearing to radiate from central area. Exciple orange, not carbonized, appearing shallowly and narrowly muti-striate (but striae made of crystalline inclusions rather than excipular tissue--visible with polarized light), these generally obscured by thalline veil, I-. Hymenium immersed and concave in section, orange, paraphyses rather thick and irregular, septate. Spores 4-locular, brownish orange, 4-6µ, 8/ascus, I-. Salazinic acid.

This specimen looks like G. grammatis in gross morphology but has distinctly orangeish hymenium, reddish-looking from above. Spores are confusing: this specimen has spores that when young are ovoid, 4 locular, and thin walled, but in age appear to darken to brown and divide once longitudinally in one cell to produce short submuriform spores. However, the brown spores are quite old and deteriorating