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 Add this item to the list  814549 Original description
   
Description type:Original description 
Description:Thallus granular to microsquamulose; when not completely granulose (soredia), squamules are broad, attached centrally to the substrate, flattened, ca. 0.1–1 mm across, little to moderately branched, often merging and closely adhering, and thus forming an almost continuous crust up to 5 mm across, blue green when fresh, dark bluish green and grey when dry, the closely adhered parts typically rimmed with a white margin (hypha only, no photobiont). Pruinose appearance present frequently, but not always on all lamina (certain squamules have scattered acanthohyphidia, which also lack soredia). Soredia present and abundant across the thallus. Thallus in cross section 100–120 µm thick, dominated by a thick photobiont layer, and with a thin cortex and medulla. Photobiont Rhizonema, clusters of densely coiled cyanobacterial filaments wrapped within a hyphal sheath formed by jigsaw puzzle-shaped cells (Cora-type). Acanthohyphidia small, 4–14 µm long and 4–7 µm wide, mostly irregular, but sometimes subglobose; present on the upper and lower surfaces, but most abundant along the thallus margins, where they sometimes become much pronounced and then resemble a prothallus; generally profuse across the upper surface of squamules that have not merged into a crust (granulose-sorediate portion). 
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