Fleuron (architectural)

A fleuron is a flower shaped ornament, and in architecture may have a number of meanings. (1) It is a collective noun for the ornamental termination at the ridge of a roof such as a crop, finial or épi. (2) It is also a form of stylised late gothic decoration in the form of a four-leafed square, often seen on crockets and cavetto mouldings. (3) It can be the ornament in the middle of each concave face of a Corinthian abacus. (4) Finally it can be a form of Anthemion, the decorative Greek floral decoration.

Fleuron as a finial.

Fleuron is the uppermost flower decoration in the center of a Corinthian capital

Fleuron in a cornice molding

Fleuron as a anthemion (Greek word for flower)

Fleuron above a doorway

...
Wikipedia