crenulate

Crenulate is an adjective used to describe an edge or margin that is finely scalloped or notched, with small rounded projections. The term comes from Latin crenula, a diminutive form related to cren- meaning notch or notch-like feature. It denotes a delicate, finely toothed outline rather than a broad or coarse tooth pattern, and is often used to indicate a very small scale of crenations.

In botanical descriptions, crenulate margins appear on leaves, petals, or other plant parts where the edge bears minute, rounded teeth. This term helps distinguish margins that are barely notched from those that are more distinctly crenate or serrate. It is commonly applied in floras, plant keys, and morphological notes to convey subtle variations in leaf or petal outline.

In zoological and paleontological contexts, crenulate margins can describe shells, teeth, or other hard structures that show fine, tooth-like notches along an edge. For example, mollusk shells or fossilized segments may be described as crenulate when their margins display many small, rounded protrusions.

Differences from related terms can be subtle: crenulate implies smaller, finer teeth or notches than crenate, while serrate indicates sharper, more pointed projections. Crenulation also serves as a noun in some contexts to refer to the presence of these small notches. The term is commonly used in morphology across botany, malacology, and paleontology to convey precise edge texture in a concise way. See also crenation and crenellation for related notions of notching and edge modification.