locule

Locule (plural locules) is a botanical term for a cavity or chamber within a plant structure that contains reproductive material, such as ovules in an ovary or pollen sacs in an anther. In fruits, locules are the compartments created by septa within the ovary; they may house seeds and influence fruit form and dehiscence.

Ovary: An ovary may be unilocular (one locule) or multilocular (two or more locules). The walls between locules are septa. Multiloculate ovaries have placental tissues distributed in different patterns, and locules can be unequal in size.

Placentation: The arrangement of ovules within locules is described by placentation terms such as axile (along a central axis in a multiloculate ovary), parietal (along the walls, typical of some unilocular ovaries with locules), free-central, and basal. These patterns help determine seed position and fruit type.

Capsule and dehiscence: In capsule fruits, the locular cavities are separated by septa, and fruit dehiscence often occurs along sutures between locules, releasing seeds. In other fruits, the locules may resemble chambers within a dry pericarp.

Anther locules: Each anther lobe typically contains pollen sacs, or locules; many angiosperms have two locules per anther, though some species have one or three or more.

Etymology and usage: Locule derives from Latin loculus, meaning small place. The term remains a standard descriptor in floral and fruit morphology and in systematic botany.