Glabrousness

Content sourced from Wikipedia, licensed under CC BY-SA 3.0.

Glabrousness comes from the Latin glaber, meaning bald or smooth. It means being hairless or without small hair-like coverings such as down, setae, or trichomes. A glabrous surface can be a natural feature of a plant or animal, or it can result from a condition that causes hair loss, like alopecia universalis in humans.

In plants and fungi, glabrous describes parts that are smooth and without hairs, bristles, or scales. If an organ starts with hairs but loses them as it ages, that is called glabrescent, not glabrous.

A familiar example is the model plant Arabidopsis thaliana, where the GLABROUS1 gene controls hair formation. Researchers study this gene to improve plant research methods, including gene editing with CRISPR.

In humans, glabrous skin appears on the fingertips, palms, soles, and lips—areas most involved in touching and interacting with the world. These skin regions have four main types of touch receptors: Pacinian corpuscles, Meissner’s corpuscles, Merkel’s discs, and Ruffini endings.

Some animals are mostly hairless. For instance, the naked mole-rat has very little body hair but retains a few scattered tactile hairs. In insects, glabrous areas are those without bristles or scales.