Definitions for "Cyathium"
the inflorescence of euphorbia (plural: cyathia).
n. (Gr. kyathos, cup) a type of inflorescence characteristic of some members of Euphorbiaceae; consisting of a cuplike involucre bearing unisexual flowers; staminate on its inner face, pistillate from the base.
Inflorescence of Euphorbia, in which a cup-like involucle surrounds a single pistil and several male flowers, each with a single stamen; flowers are sometimes bisexual.