Insertion

Insertion, the relation of the floral leaves to the receptacular portion of the flower (q.v.). The calyx (q.v.) is termed inferior if not adherent to the ovary; superior if adherent, whilst the ovary is known conversely as superior in the former case and as inferior in the latter. The corolla (q.v.) is either hypogynous (q.v.), perigynous (q.v.), or epigynous (q.v.), according as the receptacle retains the primitive tapering form of an ordinary shoot, or is expanded above into a disc or cup round (but free from) the ovary, or is adherent to it. The stamens (q.v.) are generally described as having the same insertion as the corolla; but in gamopetalous or gamophyllous flowers a zone of intercalary growth has sometimes carried both petals or perianth leaves and stamens up on a tube, which, though truly common to both, is termed a corolla-tube or perianth-tube. The stamens are then termed epipetalous, as in the hypogynous primrose and in the epigynous- Compositae, or epipkyllous, as in the hypogynous hyacinth and in the epigynous iris.

Insertion is a character of very great importance in classification.