Compound leaf
/ˈkɑmˌpaʊnd lif/
Definition
Compound leaf describes a leaf divided into separate leaflets attached to a single stalk, or petiole, rather than one undivided blade. The whole structure is still one leaf, and the leaflets do not have buds at their bases, which helps distinguish them from individual leaves on a stem. Compound leaves may be arranged palmately, with leaflets radiating from one point, or pinnately, along a central axis called a rachis.
Botanical Significance
- Identification value: A compound leaf is a key trait in plant identification because the number, arrangement, and shape of the leaflets can separate similar species and genera.
- Adaptation and light capture: Dividing the blade into leaflets can help a plant spread photosynthetic surface across space while keeping each segment relatively small and flexible in wind.
- Distinguishing from shoots: In gardening and botany, it matters to tell leaflets from true leaves. Buds form at the base of the whole leaf, not at the base of each leaflet.
- Common plant groups: This feature appears in many familiar plants, including roses, ashes, walnuts, and many legumes, so it is widely used in field guides and horticultural descriptions.
Related Terms
Leaflet
Leaflet refers to one of the individual blade-like sections of a compound leaf, where a single leaf is divided into…
Petiole
Petiole refers to the stalk that attaches a leaf blade to the stem. It is a plant structure found in many, but not all…
Rachis
Rachis is the main axis of a compound structure in plants, especially the central stem-like part of a compound leaf or…
Leaf
Leaf refers to a plant organ, usually flat and green, that grows from the stem or a branch and is specialized for…
Blade
Blade refers to the broad, flat part of a leaf, also called the lamina. It is the main surface attached to the petiole…
Pinnate
Pinnate describes a feather-like arrangement of plant parts along a central axis. It most often refers to compound…
Palmate
Palmate describes a plant form in which parts spread from one central point, like fingers from the palm of a hand. It…
Venation
Venation refers to the pattern and arrangement of veins in a leaf blade, or sometimes in other flat plant organs. It is…