Lecania

Lecania is a genus of crustose lichens belonging to the family Ramalinaceae. These lichens are characterized by their flat, crust-like growth on various substrates such as rocks, bark, and wood.

Description:

Lecania species typically exhibit a crustose thallus, which is tightly adhered to the substrate. The thallus can range in color from whitish-gray to greenish-gray or brownish. Apothecia (fruiting bodies) are generally prominent and immersed to sessile, often with a distinct margin that can be similar in color to or contrasting with the thallus. Ascospores are hyaline (translucent), ellipsoidal, and generally contain more than one cell (septate).

Distribution and Habitat:

Lecania species are found globally, with a wide distribution in temperate and arctic-alpine regions. They occupy a variety of habitats, including coastal rocks, inland siliceous rocks, tree bark (especially in woodlands and forests), and occasionally, artificial substrates like concrete.

Taxonomy:

The taxonomy of Lecania can be complex, with numerous species exhibiting subtle morphological variations. Identification often requires microscopic examination of the apothecia and ascospores. Molecular phylogenetic studies have contributed to a better understanding of species relationships within the genus.

Ecology:

Lecania lichens play a role in the ecosystems they inhabit. They contribute to rock weathering through physical and chemical processes, and they serve as a food source and habitat for invertebrates. Like other lichens, Lecania species are sensitive to air pollution and can be used as bioindicators of environmental quality.