Common Plant Terminology & Definitions

Alternate leaf arrangement

Leaves are not directly on opposite sides of the stem. They are staggered slightly.

Annual

A plant that completes its life cycle within one calendar year. It goes from seed to seed in one growing season.

Anther

The top of the stamen, which produces the pollen.

Biennial

A plant that completes its life cycle over 2 years. The first year is spent growing leaves, stems and roots. The second year is when the plant bolts upwards producing flowers and going to seed, after which the plant dies.

Bract

A modified leaf attached to the base or stalk of a flower.

Bud

An undeveloped leaf or flower of a plant.

Bulb

A specialized underground bud that sends down roots and stores water and nutrients.

Cellulose

The substance in plant cells that makes plants rigid and aids in keeping plants from collapsing.

Cotyledon

The first leaves of a seed plant. These are also called the "seed leaves."

Emersed Plant

A plant that is rooted in shallow water. Most of the vegetative growth is above water.

Native plant

A plant that is historically found in its current area. These plants are generally good for an area, as they give competition to non-native plants.

Non-native plant

Any plant that is not historically found in its current area. These plants are usually introduced into new areas by human activity or livestock.

Noxious Weeds

Noxious weeds are invasive, non-native plants that threaten agricultural crops, local ecosystems, or fish and wildlife habitats. The term 'noxious weeds' includes non-native, invasive grasses, flowering plants, shrubs, trees and aquatic plants. About half of all invasive, noxious weeds are escapees from gardens; the rest are plants accidentally introduced to Washington through human travel and trade.

Opposite leaf arrangement

Leaves are directly on opposite sides of the stem.

Perennial

A plant that grows for 3 or more years, usually flowering each year.

Rays

Narrow flowers that appear as a single petal on members of the Asteraceae (Sunflower) family. An example is dandelion.

Rhizome

A root-like stem that grows horizontally underground and produces new leaves and shoots.

Roots

The underground parts of a plant that uptake nutrients and water.

Rosette

The beginning formation of a plant after the seedling stage. It is a grouping of basal leaves.

Runner

A creeping stem that sends down new roots at spaced intervals called nodes. These nodes can form new plants and detach from the parent plant.

Stem

The main axis of a plant, the central stalk.

Stolon

A modified stem growing along the ground that develops new plants. An example is strawberry plants.

Submersed plant

Plants that develop completely under the surface of water. Leaves and flowers may eventually grow above the water surface.

Terrestrial plants

Plants that grow on land, not in water.

Weed

Any plant that crowds out cultivated or desired plants.

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