Dyplolabia
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| Dyplolabia | |
|---|---|
.jpg) | |
| Dyplolabia afzelii | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lecanoromycetes |
| Order: | Graphidales |
| Family: | Graphidaceae |
| Genus: | Dyplolabia A.Massal. (1854) |
| Type species | |
| Dyplolabia afzelii (Ach.) A.Massal. (1854) | |
| Species | |
|
D. afzelii | |
Dyplolabia is a genus of lichen-forming fungi in the family Graphidaceae. These lichens form smooth, rather thick grey-yellow to olive-buff crusts on tree bark and are characterized by narrow, elongate fruiting bodies that are commonly hidden beneath a conspicuous white powdery coating. The genus has a pantropical distribution, growing on the smooth bark of trees and shrubs in both shaded rainforest understories and moderately exposed coastal woodlands, where they serve as indicators of long-established woodland habitat.
The genus was circumscribed by the Italian lichenologist Abramo Bartolommeo Massalongo in 1854, with Dyplolabia afzelii assigned as the type species.[1]
Description
Dyplolabia produces a smooth, rather thick grey-yellow to olive-buff crust (thallus) that lacks a protective cortex. Its fruit bodies are narrow, elongate lirellae 1–6 mm long, commonly hidden beneath a conspicuous white pruina. The sides of each lirella are deeply carbonised, while the top is covered by an intact thalline layer so the slit-like disc is scarcely visible. A pale to brown excipulum lines the base, and the clear hymenium bears simple paraphyses and a green-brown epithecium. The slender asci usually contain eight hyaline ascospores that are consistently 3-septate, non-amyloid (I–) and measure about 14–20 × 6–8 μm. Most species contain only traces of lecanoric acid or are chemically inert, a feature that helps separate the genus from many chemically richer Graphidaceae.[2]
The combination of thick white pruina, strongly carbonised lirellae and small, 3-septate, iodine-negative spores distinguishes Dyplolabia from superficially similar script lichen genera. In Graphis and Glyphis the discs are exposed and the spores usually have more septa; Fissurina shares carbonised margins but lacks the heavy thalline cover; while Acanthothecis and Anomomorpha have longer or iodine-positive spores and an inspersed hymenium.[2]