Gland
/ɡlænd/
Definition
A gland is a specialized secretory structure on a plant organ, often a small cell, group of cells, or hair-like trichome that produces, stores, or releases substances such as nectar, oils, resins, salts, or digestive fluids. Glands may occur on leaves, stems, flowers, or traps. What distinguishes them is secretion: unlike ordinary surface tissue, they are adapted to make or discharge specific compounds.
Function in Plants
- Secretion and protection: A gland can release sticky, oily, salty, or sugary substances that help protect a plant from herbivores, pathogens, or excess salts, depending on the species and its habitat.
- Pollinator interactions: In flowers, a gland may produce nectar or scent compounds that attract pollinators, which can improve the chances of successful pollination and seed set.
- Identification feature: The presence, position, and type of gland can help botanists tell species apart, especially on leaves, stems, sepals, or petioles, the stalks that attach leaves to stems.
- Specialized forms: Some carnivorous plants have gland-bearing surfaces that secrete digestive fluids and absorb nutrients, showing how a gland can take on highly specialized roles in nutrient-poor environments.
Related Terms
Trichome
Trichome refers to a small hair-like or scale-like outgrowth from a plant’s epidermis, the outer cell layer. It may be…
Nectar
Nectar is a sugary liquid produced by specialized glands called nectaries, usually in flowers and sometimes on leaves…
Scent
Scent refers to the smell produced by a plant, usually from volatile organic compounds released by flowers, leaves…
Cuticle
Cuticle refers to the thin, waxy, water-resistant layer that covers the outer surface of most leaves, young stems…
Epidermis
Epidermis is the outermost layer of cells covering young leaves, stems, roots, flowers, fruits, and seeds. It is a…
Leaf
Leaf refers to a plant organ, usually flat and green, that grows from the stem or a branch and is specialized for…
Flower
Flower is the reproductive structure of a flowering plant, usually containing stamens, which produce pollen, and one or…
Stoma
Stoma refers to a microscopic pore in the epidermis, the outer cell layer of leaves and young stems. Each stoma is…