Cyphellostereum is a genus of basidiolichens. Species produce white, somewhat cup-shaped fruit bodies on a thin film of green on soil which is the thallus. All Cyphellostereum species have nonamyloid spores and tissues, lack clamp connections, and also lack hymenial cystidia.

DNA research has shown that a common, north temperate species formerly known as Cyphellostereum laeve is not related to the type species and belongs in a quite separate order, the Hymenochaetales. It has been renamed Muscinupta laevis.

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