Alternate leaf arrangement — Leaves are arranged along the stem with only one leaf at each node.

Annual — A plant that completes its lifecycle in 12 months or less.


Basal (leaf) — At or near the base of a plant or the base of a branch or trunk.

Biennial – A plant that germinates and produces foliage and roots during its first growing season, then produces flowers and seeds and dies during its second growing season.

Bract – A modified leaf, usually small, but sometimes large and brightly colored, growing at the base of a flower cluster. Bracts are sometimes mistaken for petals in plants such as dogwoods and poinsettias.

Bulb – An underground storage organ consisting of a thin, flattened stem surrounded by layers of fleshy leaf bases. Roots are attached to the bottom.


Calyx – The collective term for the sepals. (See also Sepal.)

Catkin – Flowers clustered in a spike, usually pendulous.

Compound (leaf) – A leaf in which the blade is subdivided into two or more sections called leaflets. (See also Simple [leaf].)

Crown – A short, compressed stem to which leaves and roots are attached.

Cultivar – A cultivated variety of a species.


Deciduous – A plant that sheds all of its leaves annually.

Dioecious – A plant species having separate male and female flowers on separate plants.

Drupe / Drupelets – A fleshy fruit with a hard, inner layer that surrounds the seed. Also known as stone fruit. A drupelet is a very small stone fruit.


Epiphytes / Epiphytic – A plant that grows on another plant but is not a parasite.

Evergreen – A plant that retains some or all of its foliage year-round.


Fronds – Specifically the foliage of ferns but often applied to any foliage that looks fern-like, such as palm leaves.


Globose – Ball-shaped.


Herbaceous – A soft, pliable stem that dies back to the ground at the end of the growing season.


Involucre – A cluster of bracts.


Leaflet – An individual sub-unit of a subdivided leaf.

Lenticels – A small opening on the surface of fruits, stems, trunks, and roots that allows the exchange of gases between internal tissues and the atmosphere.

Lobes – Projections on the edge of a leaf.


Midrib / Midvein – A large vein in the middle of a leaf.


Nodes / Internodes – The point on a plant where a stem, bud, or leaf develops. The space on the stem between nodes is an internode.


Obovate – An oval shape that is narrower at the base than the tip.

Opposite leaf arrangement – Leaves are arranged along the stem with two leaves at each node.


Palmately – Radiating outward from a single point, somewhat like the fingers of a hand. A term used to describe the arrangement of leaflets in some compound leaves and the arrangement of veins within a leaf blade.

Perennial – A plant that lives three or more years.

Petiole – The stalk that attaches the blade of a leaf to the stem.

Pinnae – An individual sub-unit of a subdivided frond.

Pinnate / Bipinnate – Radiating outward from a central axis, somewhat like the divisions of a bird feather. Terms used to describe the arrangement of leaflets in some compound leaves and the arrangement of veins within a leaf blade.

Propagated – Started new plants by cutting, seeding, layering, grafting, dividing, etc.


Rhizome – A horizontal underground stem.

Rosette leaf arrangement – A small cluster of leaves radially arranged in an overlapping pattern attached to a short, compressed stem on plants such as dandelions.


Scalloped – Shallow, curved teeth similar to the edge of a scallop shell.

Sepal – The outermost flower part, typically green or greenish and more or less leafy in appearance. Sepals enclose the other parts of the flower within a flower bud.

Sheathing – A protective cover.

Simple (leaf) – A leaf that is not divided into separate pieces.

Species – The basic unit of plant classification.

Spur – On fruit trees, a short, compact twig on which flowers and fruit are borne. In flowers, a hollow extension of a petal.

Stamen – The male, pollen-producing part of a flower.

Succulent – A type of plant with thickened stems and leaves for storing water. Fleshy and tender with regard to new growth.


Tendrils – A slender projection from a stem used for clinging or climbing, usually a modified leaf. Examples include grapes, clematis, peas, and cucumbers.

Terrestrial – Growing in soil rather than in the air or on the bark of trees.

Tuberous (root) – A modified root enlarged for storage of food reserves found in dahlias and sweet potatoes, for example.


Umbels – A flower cluster in which stalks are of nearly equal length from a common center, similar to an umbrella shape.


Whorled leaf arrangement – Leaves are arranged along the stem with three or more leaves at each node.

Woody – A plant that produces hard (rather than fleshy) above-ground stems that survive winter and continue to grow in diameter each year. Examples include trees, shrubs, and some vines.