Lamella

Lamella, plural lamellae, is a term used across biology and materials science to denote a thin plate, layer, or membrane that forms part of a larger structure. The lamella concept emphasizes a subunit that can influence a tissue’s strength, transparency, or functional arrangement.

In fungi, lamellae are the gill-like plates on the underside of a mushroom cap where spores are produced. The arrangement and density of lamellae help distinguish species and affect spore dispersal. In plant cells, lamellae refer to internal membrane systems such as the thylakoid membranes within chloroplasts; these lamellae connect grana and play a central role in photosynthesis by providing a large surface area for light-dependent reactions.

In animal tissues, lamellae appear in several contexts. Bone tissue contains lamellae—concentric layers of mineralized matrix that surround Haversian canals, forming organized osteons in mature, lamellar bone. The cornea also contains collagen lamellae arranged in a highly regular pattern to maintain transparency and mechanical strength. In some cases, dentin exhibits dentinal lamellae as layered structures within tooth structure.

In materials science, lamellae describe thin, plate-like layers in layered or crystalline materials. Lamellar structures arise in polymers during semicrystalline crystallization and in inorganic layered materials such as graphite, where alternating lamellae contribute to anisotropic properties and fracture behavior. The concept of lamellae is thus used to describe recurring thin plates or membranes that influence function and mechanical performance across diverse fields.