integumental

Integumental is an adjective used in biology to refer to structures or tissues related to an integument, the outer protective covering of an organism or of a particular organ. The term is applied in multiple contexts, reflecting the diversity of protective coverings in living beings.

In animals, the integument or integumentary system comprises the skin and its derivatives, such as hair, scales, feathers, nails, and glands. This system functions as a barrier against environmental hazards, regulates temperature, participates in sensation, and engages in immune defense and excretion. Integumental tissues include the epidermis and underlying dermis, along with associated structures that develop from these layers.

In plants, integumental describes tissues surrounding the ovule. The integument is a protective layer (or two layers: outer and inner) that envelops the nucellus and embryo sac. In angiosperms, most species have two integuments, and after fertilization these layers often harden to form part of the seed coat, with the outer integument contributing to the testa and the inner to the tegmen. The micropyle is the opening located at the apex of the integuments through which pollen tubes typically enter during fertilization. In gymnosperms, ovules commonly have a single integument.

The term can also be used more broadly to describe cells or tissues that contribute to these protective coverings, including integumental layers in developing seeds or fruit, and, in an anatomical context, various superficial coverings of organs.