lamelles

Lamellae (singular lamella) are thin plate-like structures that occur in a wide range of biological, geological, and materials contexts. The term derives from Latin lamella, meaning a small plate, and is used to describe flat sheets that separate, connect, or organize other structures.

In mycology, lamellae are the gill-like plates on the underside of a mushroom cap. They form a hymenium in which basidia produce basidiospores. Lamellae can be attached to the stalk, free, or decurrent, and their size, spacing, and coloration are important for species identification and classification.

In anatomy and histology, lamellae denote thin layers of tissue or mineralized matrix. In bone, lamellae are the concentric layers of mineralized bone matrix surrounding Haversian canals, assembling into mature lamellar bone. In plants, the middle lamella is a pectin-rich layer between adjacent cell walls; chloroplasts contain stroma lamellae that connect grana stacks in photosynthetic membranes.

In materials science and geology, lamellae describe layered or plate-like structures observed in minerals, rocks, and engineered composites. Such lamellar organization can influence texture, mechanical properties, and fracture behavior, and is a focus of study in fields ranging from paleontology to biomimetics.