spinulate

Spinulate is an adjective used in biological description to indicate that a surface or structure bears spinules, which are very small spine-like projections. The term is formed from spinula, a diminutive of spine, and follows standard scientific naming conventions for surface ornamentation.

In descriptive morphology, spinulate surfaces are noted on a variety of biological materials, including seeds, pollen grains, spores, scales, and the cuticle or integument of invertebrates. The presence of spinules can influence texture and interactions with the environment, such as adhesion, microhabitat retention, or how a specimen is observed under microscopy. In palynology, for example, pollen exine ornamentation is often described as spinulate when it bears minute spinules; similar terminology appears in the study of seeds and other plant and animal structures.

Spinulate is related to, but distinct from, related terms such as spinose (bearing spines) and spinulose (bearing very small spines). The exact meaning can vary somewhat by discipline and author, but all terms share the general idea of surface ornamentation formed by small projections rather than smooth or uniformly coarse textures.

See also: morphology of surface ornamentation, palynology, taxonomy, integument, spinule.