Parts of a Leaf:
Apex
Veins
Secondary Veins
Teeth
Midrib/Midvein
Base
Petiole
Blade
Stalk
Stipule
Venation refers to the layout (the network veins form)

Margin Types:
(refers to the edge of the leaf)
Entire: Smooth Edge
Serrate: Teeth like a saw, continuous and forward pointing
Dentate: Continuous teeth that point outwards
Doubly Dentate:
Crenate: Like dentate but with teeth rounded

Most Common Leaf Shapes within Forestry:
Entire
Sinuate
Crenate
Serrate
Doubly Serrate
Dentate
Lobed
Parallel
Pinnate
Arcuate
Cordate
Palmate

Linear: Long and slender, with margins that are almost parallel.
Lanceolate: Broadest just below the center, and 3 to 6 times longer than its width.
Ovate: Widest below the center, and about 1.5 to 2 times as long as it is wide (egg-shaped).
Elliptic: Widest at the center, with curved edges and pointed ends at both the tip and base.
Oblong: Rectangular shape with nearly parallel sides, and about twice as long as wide.
Oval: Widest at the center, with curved edges and rounded ends at both the tip and base.
Rhombic: Diamond-shaped, widest at the center, with straight edges.
Deltoid: Triangular, resembling an equilateral triangle (having all its sides the same length).
Oblanceolate: A reverse of lanceolate, widest above the center of the blade.
Spatulate: Spoon-shaped, similar to oblanceolate but with a narrow (tapered) base.
Obovate: A reverse of ovate, widest above the center of the blade.
Orbicular: Circular, with rounded edges.
Scale-Like: Reduced in size, flat and sharp-pointed or blunt.
Subulate: Awl-shaped, narrow and pointed, rounded in cross section (awl means narrowly triangular and sharply pointed/ typically broad at the base and tapers to a slender, stiff, sharp point, although the tip can vary, such as being diamond-shaped or circular).
Acicular: Needle-like, very narrow and pointed, rounded in cross section.
Runcinate: Oblanceolate with jagged or torn edges (Runcinate leaves are pinnately incised (cut in a feather-like pattern) with the lobes curved back toward the base of the leaf).
Fan-Shaped: A leaf with a blade that spreads out like a semi-circle.
Peltate: A leaf where the petiole is attached near the center of the underside of the blade.
Cordate: Heart-shaped, with a pointed tip and two rounded lobes at the base.
Obcordate: Reverse heart-shaped, with a narrow base and two rounded lobes at the tip.
Reniform: Kidney-shaped, with a broad, rounded tip and two rounded lobes at the base.
Sagittate: A leaf with pointed basal lobes that point downward or inward.
Hastate: A leaf with pointed basal lobes that point outward or away from each other.
Auriculate: A leaf with small, rounded lobes at the base, resembling ears.
Lyrate: Lyre-shaped, similar to oblanceolate but with two or more smaller lobes toward the lower part of the leaf.
Panduriform: Fiddle-shaped, similar to oblanceolate but with two small lobes at the bottom.

Similar leaf shapes (keep in mind sometimes a single leaf sample may not have key ID features such as twig, bark and form)

Ironwood and Yellow Birch
Balsam Fir and Eastern Hemlock (Both have stripes)
Red Pine and Austrian Pine (Red Pine needles snap)


(Northern Ontario Flora, ChatGPT, Algonquin College Forestry Technician program field notes)