Circular areas on a surface that are divided from similar areas by a division line such as a vein;
Usually flat area on each side of some mimosoid legume seeds that is surrounded by the pleurogram;
In Cactaceae, the spine-bearing cushion; extremely reduced branches (axillary buds) that usually bear spines, but can also become stems or flowering branches.
A small protrusion or depression, such as those scattered across the surface of cacti stems.
On cacti, a small, hairy bump that produces a cluster of longer spines.
A raised area in a cactus from which spines develop.
A more or less circular area that is divided from similar areas by a line such as a vein, often used in description of venation types. The term is also used to describe the spine-bearing areas in cacti.
The swelling on the stem of a cactus which bears the spines It is actually the vestigial remains of a shoot.
A specialized structure characteristic of the cactus family, consisting of a small pad of tissue from which arise spines, hairs, and flowers. Areoles are always positioned along the ribs of a cactus stem or at apices of stem tubercles; they are interpreted as highly modified and condensed lateral shoots.