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Buellia Oidalea
''Buellia oidalea'' is a species of crustose lichen found along the Pacific coast of North America, from Coos County, Oregon to Baja California Sur. Morphology The thallus of ''B. oidalea'' is crustose, varying from thin and rimose-areolate to thick and rugose-verrucose or even subsquamulose. The prothallus is often present, appearing black. The thallus surface is yellowish white to glaucous gray, smooth, and esorediate. The Medulla (lichenology), medulla is white and lacks calcium oxalate.Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2. The apothecia of Buellia oidalea are lecideine and commonly found, ranging from 0.2 to 2 mm in diameter, and are sessile in nature. Initially, the disc is black, devoid of Pruina (lichen), pruina, and flat, but as it matures, it becomes convex. The margin starts as distinct but eventually becomes excluded and black. The proper exciple measures between 35 and 95 μm in thick ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crustose Lichen
Crustose lichens are lichens that form a crust which strongly adheres to the Substrate (biology), substrate (soil, rock, tree bark, etc.), making separation from the substrate impossible without destruction. The basic structure of crustose lichens consists of a cortex (botany), cortex layer, an algal layer, and a medulla. The upper cortex layer is differentiated and is usually pigmented. The algal layer lies beneath the cortex. The medulla fastens the lichen to the substrate and is made up of Fungus, fungal hyphae. The surface of crustose lichens is characterized by branching cracks that periodically close in response to climatic variations such as alternate wetting and drying regimes. Subtypes * Powdery – considered as the simplest subtype due to the absence of an organized thallus. :The thallus appears powdery. :E.g. Genera ''Lepraria'', ''Vezdaea'' * Endolithic – grows inside the rock, usually in interstitial spaces between mineral grains. The :upper cortex is usually d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
