Abaxial
The side pointing away from the axis, usually the underside of a leaf, stem or branch.
Abscission
The loss of a structure, such as a leaf, due to a chemical process where cells form a callous layer blocking food and water causing the structure to fall off.
Accessory Bud
Buds that are not found in the axils of the leaves but are often found above or adjacent to axillary buds at a node.
Acerose
Narrow elongated leaf; Needle-shaped.
Acuminate
Sides curving concavely upward and inward then tapering to a fine point on the leaf apex.
Acute
An angle that is less than 90º with straight lines and having a point on a leaf apex.
Adaxial
The side toward the axis, usually the upper surface of a leaf, stem or branch.
Alternate
Leaves or stems situated one at a node. Leaves can alternate in a distichous pattern 180º apart along two sides of the stem, or at lesser angles around a stem.
Anther
A section of the male part of a flower containing the pollen.
Apetalous
Lacking petals.
Apex
The top; the terminal portion of a leaf; plural is apices.
Apiculate
A leaf or petal having a short slender point that is flexible.
Appressed
Firmly against another object, as a bud to a stem.
Arching
Branches of shrub (or any part of plant) that curves outward from the main body of the shrub.
Asymmetric
A plant part that has an irregular shape. (See also Oblique).
Attenuate
Leaf tissue tapers down the petiole (toward the base) to a narrow base always having some fleshy leaf on either side of the petiole.
Auriculate
Ear-lobed shaped leaf base(s) attached to petiole.
Awl-shaped
Tapering to slender stiff point; Short stiff margins narrowing to a point, often sharp and found on young Junipers.
Axil
The angled point on a stem where the leaf (or petiole) attaches to the stem.