Palmate

Palmate is an adjective used in botany to describe structures that radiate from a common point, resembling the palm of a hand. The term, from Latin palma meaning palm, is commonly applied to leaf form and venation, among other plant features.

In leaves, palmate describes two related patterns. Palmately lobed leaves have lobes that spread outward from a single point at the blade where the petiole attaches, creating a hand-like silhouette. Maple leaves are a well-known example. Palmately compound leaves consist of multiple leaflets that all attach at the end of the petiole at a single point, as seen in Virginia creeper or horse-chestnut. These two usages are distinct: lobing refers to the blade’s margins, while compound describes separate leaflets.

Palmate versus other leaf patterns: the term contrasts with pinnate, where leaflets are arranged along a central axis or rachis rather than all from a single point at the base. Some leaves may be described as palmately lobed or palmately compound, but not both simultaneously.

Apart from leaves, palmate can describe other plant features that originate from a single point. Palmate venation, for example, refers to several primary veins radiating from the base of the leaf. In flowering parts, a palmately arranged set of petals or sepals can also be described as palmate in some contexts.

See also: leaf morphology, venation patterns, plant terminology.