Taxonomy
The genus was circumscription (taxonomy), circumscribed in 1860 by Swiss lichenologist Abramo Bartolommeo Massalongo, with ''Leucodecton compunctum'' assigned as the type species.Description
''Leucodecton'' forms a thin, crustose lichen, crust-like thallus that lies flat on the bark or rock surface. Its upper layer is usually cream to pale fawn (colour), fawn; the outer "skin" () is only weakly developed, giving the surface a smooth to slightly knobbly look. Large, irregular crystals may be embedded in the interior, but the border () that some lichens display is missing. Vegetative propagules used for asexual reproduction, asexual spread—powdery soredia or tiny finger-like isidia—occasionally occur. The photosynthesis, photosynthetic partner is a filamentous green alga from the genus ''Trentepohlia (alga), Trentepohlia'', which lends an orange tint when exposed in damaged areas. The reproductive bodies are flask- to urn-shaped apothecia that start out immersed in the thallus and often push up in small wart-like clusters. Their black are usually concave, sometimes dusted with a grey bloom (), and are framed by a rim of thallus tissue () that may split irregularly as the fruiting body matures. Beneath this rim lies a —an internal ring of densely intertwined fungal hyphae—seen in a view from above. Within the apothecium, the colourless hymenium houses slender ascus, asci, each with a single functional wall layer that thickens abruptly at the tip. The asci typically hold one to eight ascospores. Spores are elongated to spindle-shaped, with several internal walls; they begin colourless and thin-walled but often darken and develop thick, laminated walls as they age. No conidiomata (structures that produce asexual reproduction, asexual spores) have been observed. Chemically, most species produce stictic acid, stictic or norstictic acid, secondary metabolites that are useful for species identification through thin-layer chromatography.Species
, Species Fungorum (in the Catalogue of Life) accepts 32 species of ''Leucodecton'': *''Leucodecton albidulum'' *''Leucodecton album'' *''Leucodecton anamalaiense'' *''Leucodecton biokoense'' *''Leucodecton bisporum'' *''Leucodecton canescens'' – Sri Lanka *''Leucodecton compunctellum'' *''Leucodecton compunctum'' *''Leucodecton confusum'' *''Leucodecton coppinsii'' *''Leucodecton dactyliferum'' *''Leucodecton desquamescens'' *''Leucodecton elachistoteron'' *''Leucodecton fissurinum'' *''Leucodecton fuscomarginatum'' – Sri Lanka *''Leucodecton glaucescens'' *''Leucodecton granulosum'' *''Leucodecton inspersum'' *''Leucodecton isidioides'' *''Leucodecton minisporum'' *''Leucodecton nuwarense'' *''Leucodecton occultum'' *''Leucodecton oxysporum'' *''Leucodecton phaeosporum'' *''Leucodecton pseudostromaticum'' *''Leucodecton pustulatum'' *''Leucodecton sordidescens'' *''Leucodecton sorediiferum'' *''Leucodecton subcompunctum'' *''Leucodecton tarmuguliense'' *''Leucodecton uatumense'' *''Leucodecton willeyi''References
{{Taxonbar, from=Q6534132 Graphidaceae Lichen genera Graphidales genera Taxa described in 1860 Taxa named by Abramo Bartolommeo Massalongo