Difference between revisions of "Crustose"

'''crustose''' (''adj.''; ''alternative spelling:'' [[crustaceous]]; the spelling ''crustose'' is preferred since ''crustaceous'' is commonly used to describe hard-shelled animals, i. e., crustaceans) – general growth form where the entire thallus forms a crust, i. e., the lower surface without a cortex and directly attached to the substrate, removed only with difficulty and most generally not without destroying or damaging the thallus. The crustose growth from ''includes'' [[granular]], [[rimose]], [[areolate]], [[placodioid]], [[lobate]], [[squamulose]], and [[peltate]] thalli. Poorly differentiated and / or loosely aggregated thalli such as [[filamentose]] or [[leprose]] are also treated here, even though they are not, strictly speaking, forming distinct crusts. Other categories treated here represent transition forms. Thus [[squamulose]] and lobed thalli may be considered [[subfoliose]]. Minutely fruticose or [[dactyliform]] thalli are [[subfruticose]]. Crustose thalli are rarely continuous but usually organized in smaller units like areoles or squamules.