| Halegrapha kenyana | |
|---|---|
Scientific classification  | |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lecanoromycetes |
| Order: | Graphidales |
| Family: | Graphidaceae |
| Genus: | Halegrapha |
| Species: | H. kenyana |
| Binomial name | |
| Halegrapha kenyana | |
Halegrapha kenyana is a species of script lichen in the family Graphidaceae. [1] 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.
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. [2]
In the original description, the species was described as having been initially labelled as "Graphis / Phaeographis", alluding to its intermediate set of characters . The authors considered it most similar to H. floridana , but separated it by its clear (non- inspersed ) hymenium, a thin, bowl-shaped excipulum , and the presence of stictic acid chemistry. [2]
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 prothallus . In cross-section, the thallus has a cartilaginous upper cortex, an irregular photobiont layer , and conspicuous clusters of crystals. [2]
The fruiting bodies are lirellae (elongate, slit-like apothecia) that are dense, flexuose , and irregularly branched. They are immersed to erumpent, with the base set well below the thallus surface and a white lateral thalline margin . The disc is concealed and the black labia become striate with age. Microscopically, the excipulum is bowl-shaped and completely carbonized (blackened), 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 (with K+ persistently yellow in microscope cross-sections). [2]
Halegrapha kenyana is a corticolous (bark-dwelling) lichen known from coastal Kenya, where it was collected in the Shimba Hills (Kwale District) at 350 m elevation. In the original description, the species was reported only from the type collection, and no further localities or habitat details were provided beyond its occurrence on bark at the type locality. [2]