Glossary of leaf morphology

Glossary of leaf morphology is a comprehensive list of terms and definitions used to describe the various parts and types of leaf morphology in botany. Leaf morphology refers to the study of the form and structure of leaves, which are the primary photosynthetic organs of plants.

Overview

Leaf morphology is a critical aspect of plant identification and taxonomy. The shape, size, and other physical attributes of leaves can provide valuable information about a plant's species, genus, and family. This glossary provides definitions for the most commonly used terms in leaf morphology.

Glossary

A

• Apex: The tip of a leaf or other plant organ.
• Axil: The angle between the upper side of a leaf or stem and the supporting stem or branch.

B

• Base: The part of a leaf that is attached to the stem or branch.
• Blade: The broad, flat part of a leaf.

C

• Compound leaf: A leaf that is divided into multiple leaflets.
• Cordate: Heart-shaped, with the petiole or stem attached to the notch.

D

• Deciduous: Referring to plants that shed their leaves annually.
• Dentate: Having a toothed margin.

E

• Entire: Having a smooth margin without teeth or lobes.
• Evergreen: Referring to plants that retain their leaves year-round.

F

• Foliage: The collective term for all the leaves of a plant or tree.
• Frond: A large, divided leaf, especially in ferns and palms.

G

• Glabrous: Smooth, without hairs or scales.
• Glaucous: Covered with a whitish or bluish waxy coating or bloom that is easily rubbed off.

H

• Hastate: Arrowhead-shaped with the basal lobes pointing outward.
• Hirsute: Covered with coarse or stiff hairs.

I

• Imbricate: Overlapping, as in the shingles on a roof.
• Incised: Deeply cut.

J

• Jugate: Paired, as in leaflets.

K

• Keeled: Having a prominent raised central ridge.

L

• Lanceolate: Lance-shaped, longer than wide, tapering to a point at the apex.
• Lobed: Having projecting segments.

M

• Margin: The edge of a leaf.
• Midrib: The central vein of a leaf.

N

• Node: The point on a stem where a leaf or leaves are attached.
• Nervation: The arrangement of veins in a leaf.

O

• Opposite: Leaves or buds arranged in pairs along the stem.
• Ovate: Egg-shaped in outline, with the broader end at the base.

P

• Palmate: Having several lobes whose midribs all radiate from one point.
• Petiole: The stalk that attaches the leaf blade to the stem.

Q

• Quinate: Arranged in a group of five.

R

• Reticulate: Net-like, as in the pattern of veins in a leaf.
• Rosulate: Arranged in a rosette.

S

• Serrate: Having a margin with sharp, forward-pointing teeth like a saw.
• Simple leaf: A leaf that is not divided into leaflets.

T

• Trifoliate: Divided into three leaflets.
• Turgid: Swollen or distended.

U

• Undulate: Having a wavy margin or surface.

V

• Vein: The vascular tissue of a leaf.
• Venation: The arrangement of veins in a leaf.

W

• Whorl: Three or more leaves or branches at a single node.

X

• Xerophyte: A plant adapted to survive with little water.

Y

• Yucca: A genus of perennial shrubs and trees with stiff, sword-shaped leaves.

Z

• Zygomorphic: Bilaterally symmetrical, so a line drawn through the middle would create two mirror-image halves.

See also

• Leaf shape
• Leaf size
• Leaf venation
• Leaf arrangement