Halegrapha kenyana
Halegrapha kenyana is a species of script lichen in the family Graphidaceae. It forms a thin, yellowish-white crust on tree bark and produces dense, black, slit-like fruiting bodies. The species is known only from the Shimba Hills in coastal Kenya.
Taxonomy
Halegrapha kenyana was formally described in 2011 by Klaus Kalb and Robert Lücking, in the same work that established the genus Halegrapha for a small group of tropical, bark-dwelling species with a Graphis-like appearance but brown, septate spores typical of the Phaeographis lineage.In the original description, the species was described as having been initially labelled as "Graphis / Phaeographis", alluding to its intermediate set of. The authors considered it most similar to H. floridana, but separated it by its clear hymenium, a thin, bowl-shaped, and the presence of stictic acid chemistry.
Description
Halegrapha kenyana forms a thin, continuous thallus on bark, usually 1–3 cm across and about 50–80 μm thick. The surface is smooth to uneven and yellowish white, without a distinct. In cross-section, the thallus has a upper cortex, an irregular, and conspicuous clusters of crystals.The fruiting bodies are that are dense,, and irregularly branched. They are immersed to erumpent, with the base set well below the thallus surface and a white lateral. The is concealed and the black labia become striate with age. Microscopically, the excipulum is bowl-shaped and completely, while the hymenium is colourless and clear; the asci contain eight brown ascospores, usually 3–5-septate, measuring about 13–18 × 5–7 μm. Thin-layer chromatography detected stictic acid as a major lichen product with constictic acid as a minor component.