nervure

Nervure is a term used in botany and entomology to describe a vein or nerve-like structure, especially a major vein in a leaf or a wing. The word comes from the French nervure, meaning nerve or nerve-like ridge.

In botany, nervures are the vascular strands that form the framework of a leaf. They include the central midrib and the network of secondary and sometimes tertiary veins. Nervures provide mechanical support for the lamina, aid in the transport of water, minerals, and photosynthates, and influence the leaf’s rigidity and flexibility. Leaves may show different venation patterns, such as pinnate venation with a single main midrib and lateral veins, or palmate venation with several primary veins radiating from a common point. Reticulate or net-like nervure patterns are common in many dicot leaves. The arrangement and development of nervures are important characters in plant taxonomy and are frequently studied in paleobotany because venation patterns can be preserved in fossils.

In entomology, nervures refer to the network of longitudinal and cross veins in an insect wing. They provide structural support during flight and contribute to wing shape and stability. Wing venation is highly diagnostic, with characteristic sets of veins named or abbreviated (for example, Costa, Subcosta, Radius, Media, Cubitus, and Anal veins in many taxa), along with numerous cross-veins that form closed cells. The pattern and completeness of nervures vary among orders and species and are widely used in taxonomic identification and phylogenetic analysis.

In English, nervure is chiefly a technical term encountered in botanical and entomological contexts and is often used alongside more common terms like vein or venation.