soralium (noun, pl. soralia) – a distinctly delimited thallus area where soredia are formed. – OR – A decorticate area or body of the thallus where soredia are produced; a conspicuous clump of soredia, usually "limited" with a definite boundary or margin and occurring in constant patterns on the thallus; can be in many forms. Related terms: cuff-shaped soralium, fissural soralium, laminal soralium, linear soralium, marginal soralium, nodule, rimiform soralium. This is:part of thallus surface. Kind of:upper surface structure.