Adnation

In botany, adnation is the fusion of two or more whorls of a flower, e.g. stamens to petals, within angiosperms (flowering plants).^[1] This is in contrast to connation, the fusion among a single whorl.^[2][3]

The stamens of Primula vulgaris are adnate to the corolla

The tropical pitcher plant Nepenthes adnata is named for its adnate leaf bases