Aquatic Plant Identification Glossary
We’ve provided a glossary of plant identification terms to aid in your plant species determination.
Alternate Leaves – leaves spaced singly along a stem, one at each node.
Axil – the angle between two structures on a plant, such as the notch created between the stem and the base of a leaf.
Blade – the expanded portion of a leaf, in contrast to the leaf stalk.
Bract – a reduced or modified leaf that is located just below a flower or flower stalk.
Canopy – a cluster of leaves and branching stems on or near the water surface.
Capsule – a dry fruit with more than one seed that opens at maturity.
Cuticle – the waxy protective layer on the surface of a leaf or stem.
Detritus – any disintegrated matter; debris, such as loose organic matter composed of parts of decaying plants.
Divided – a plant structure that is cut into distinct parts; often used to describe divisions of a leaf.
Entire – a leaf margin that is smooth, not toothed or lobed.
Epiphyte – a plant that grows on another plant, but does not take its food or water from that plant.
Fruit – a ripened ovary, along with any other structures that mature with it and form a unit.
Heterophylly – the presence of two different kinds of leaves on the same plant.
Keel – a sharp ridge.
Midrib – the central vein of a leaf that runs from its base to tip.
Node – the place on a stem where a leaf or branch arises.
Nutlet – a small, dry, one-seeded fruit with a hard wall.
Opposite leaves – leaves arranged along a stem in pairs, directly across from each other.
Ovary – the part of a flower’s female reproductive structure that encloses the seeds.
Petal – an inner floral leaf, usually colored.
Petiole – leaf stalk.
Rhizome – a creeping, underground stem.
Rosette – leaves arranged in a radiating pattern at the base of a plant.
Serrate – a sharply toothed leaf margin.
Sheath – the portion of a leaf that wraps around the stem.
Spike – flowers closely spaced on a single stalk.
Spore – A single-celled reproductive structure produced by non-flowering plants.
Stipule – an appendage of tissue on the stem at the base of a leaf stalk.
Stolon – a stem that creeps along the surface of the sediment or ground.
Tuber – the thickened portion of a rhizome, providing food-storage for the plant.
Turion – a specialized overwintering structure.
Whorl – an arrangement of leaves, bracts or flowers with three or more radiating from a common point.
Winter bud – A shortened branch with tightly spaced, often reduced leaves. This structure survives the rest of the plant over winter and renews growth in the spring.