peltate

Peltate is a botanical term describing a leaf or leaf-like structure in which the petiole attaches to the underside of the blade away from the margin, often near the center, so the lamina radiates outward from the attachment point. The word derives from Latin peltatus, meaning shield-shaped.

This arrangement contrasts with leaves that are attached at the base by a petiole (petiolate) or directly fused to the stem (sessile). Peltate leaves are typically more circular or reniform in shape, and their venation tends to radiate outward from the attachment point.

Common examples include Tropaeolum majus (nasturtium), which has round, peltate leaves; several aquatic plants such as Nymphaea (water lilies) and Brasenia schreberi (water shield), whose leaves are peltate and adapted to floating or submersed conditions. Begonia species can also exhibit peltate leaves.

In ecology, peltate leaves are sometimes associated with aquatic or wetland habitats, where the attachment position may influence light capture, buoyancy, or stability. The morphology can vary, with some peltate leaves nearly circular and others more irregular in outline, but the defining feature remains the central or near-central attachment of the petiole to the leaf underside.

See also: leaf morphology, petiole, foliar attachment.