Understanding Calypters in Botany: Protective Leaf Modifications

Calypter (plural: calyptra) is a term used in botany to describe a type of leaf modification that occurs in some plant species. It refers to the process by which the leaf blade is modified to form a protective cover or sheath around the stem, often near the base of the plant.

The calypter can be made up of any part of the leaf, including the petiole (stalk), the rachis (midrib), or the lamina (blade). The modification can take various forms, such as a cup-like structure, a hood, or a folded or crinkled shape. The purpose of the calypter is to protect the stem and surrounding tissues from damage, such as from herbivores, wind, or water.

Calyptra are found in many plant families, including Acanthaceae, Apocynaceae, Asclepiadaceae, and Malpighiaceae. Some examples of plants with calyptra include the African milk tree (Commiphora wildii), the corktree (Cochlospermum regium), and the jade vine (Strongylodon macrobotrys).