serrulate

Serrulate is a botanical term used to describe a margin or edge that bears very fine, regularly spaced teeth. The teeth are small and delicate, giving a finely saw-toothed appearance that is subtler than a typical serrate margin. The term is often used descriptively in plant morphology to convey a particular scale of marginal teeth in leaves, leaflets, petals, or other plant structures.

In botanical descriptions, serrulate margins are contrasted with serrate margins, which have larger or more pronounced teeth, and with dentate margins, where teeth are typically broader and more protruding. Crenate margins, by contrast, have rounded teeth. There is no universal cut-off value for what constitutes “serrulate,” and the designation is largely relative and context-dependent, serving as a qualitative character in taxonomic keys and species descriptions.

Applications of the term span a wide range of plants, from herbaceous species to woody taxa, and it is also used in paleobotany to describe fossilized plant material where small marginal dentitions are preserved. While serrulate margins can occur in various taxa, the common thread is the presence of fine, evenly spaced marginal teeth that are subtler than those described by serrate. The word derives from Latin serrula, a diminutive form of serra, meaning saw.