piliform

Piliform is an adjective used in biology and related fields to describe structures that are slender, thread-like, or hair-like in form. Derived from the Latin pilus, meaning hair, and the suffix -form meaning in the shape of, piliform roughly translates to “hair-shaped.” The term is applied across disciplines to indicate filamentous morphology rather than a specific taxonomic grouping.

In botany and plant sciences, piliform can describe trichomes or other outgrowths that are slender and hair-like on leaves, stems, or seeds. In microbiology and mycology, piliform may refer to thread-like bacteria or filamentous fungi that exhibit elongated, filamentous cellular structures. In histology and anatomy, certain tissues or cellular components may be described as piliform when their appearance is long and narrow, such as elongated projections or fibers.

Because piliform is a descriptive term rather than a strict classification, its precise meaning depends on context, and it is often used alongside other descriptors such as size, arrangement, or staining characteristics. Some sources may use related terms such as filamentous, thread-like, or piliform to convey similar morphology.