Leaf Identification to identify broad and narrow shaped leaves to identify simple and compound leaf groupings to identify leaf arrangement to identify leaf margin characteristics to identify leaf venation to identify leaf structure
Leaf Structure The Leaf Blade The blade is the entire leaf unit. Sometimes this is made up of several smaller leaflets.
Leaf Veins
Leaf Margin The margin is the term used to describe the edge of the leaf.
Leaf Base Base is the name given to the part of the blade that is closest to the stem.
Leaf Apex The Apex is the tip of the leaf.
Petiole The Petiole is the thin stalk that connects the leaf blade to the stem
Stipule Stipules are tiny leaf-like structures that may or may not be present at the base of the petiole.
Petiolate and Sessile Leaves which have petioles are called Petiolate If a leaf has no petiole it is called Sessile.
Seven Main Leaf Structures
Leaf Blade The main part of a leaf is the blade. Nine major shapes Linear Lanceolate Oblong Elliptic Ovate Cordate Reniform Spatulate Orbicular
Linear Narrow, with parallel or nearly parallel side
Lanceolate lance shaped, longer than broad and tapering to a point at the tip
Oblong Much longer than wide, with nearly parallel sides
Elliptic Shaped like an ellipse, wider at the center and tapering to equal tips
Ovulate egg-shaped, broader at the base than the tip
Cordate Heart shaped, either the leaf shape or base
Reniform Kidney shaped
Spatulate In the shape of a spatula or spoon
Orbicular Round
Leaf Groupings How leaves are grouped on stem Simple Compound
Three types of compound
Leaf Margins The shape of the edge or margin of a leaf is another way it can be identified. Three kinds of margins are Entire, Toothed, and Lobed.
Entire Smooth no bumps
Toothed Shallow bumps
Dentate Pointing outward
Serrate Point to the leaf’s tip
Crenate Broad and round
Incised deeply cut with sharp, irregular teeth
Lobed deep indents or sinuses
Sinnate very wavy margin
Undulate wavy margin, but not as wavy as a sinuate margin