1. Leaf Identification
Topic 2014A and 2014 D
Amanda Trutsch

2. Characteristics of: Monocot Dicots Embryo with single cotyledon
Flower parts in multiples of three
Major leaf veins parallel
Dicots
Embryo with two cotyledons
Flower parts in multiples of four or five
Major leaf veins reticulated (net venation)

3. Monocot

4. Dicot http://gecko.gc.maricopa.edu/~lsola/Flower/hibisc.jpg

5. Types of Leaves Broadleaf Conifer Broad, flat leaf
Also called hardwoods
Many are decidious
Ex: maple, oak, birch
Conifer
Needle-shaped or scale-like leaves
Also called softwood
Ex: White pine, juniper, yew

6. Conifer Broadleaf http://www.istockphoto.com

7. Broadleaves

8. Leaf Parts to Look At:
(apex)

9. Characteristics to look for:
Leaf arrangement
Leaf composition
Overall shape
Leaf tip
Leaf margin
Leaf base

10. Leaf Arrangement on Stem
Alternate Opposite Whorled
Three or more leaves
attached to a
single node
Two leaves attached to
the same node
One leaf attached to a node

11. Leaf Composition Simple Compound A leaf with only one
leaf blade area
A leaf with more than
one leaf blade area

12. Types of Compound Leaves
Pinnate Compound Palmate Compound
Leaflets arranged along
a central axis like a feather
A leaf with multiple leaf
blade areas where the leaflets
are attached to a common point

13. Types of Compound Leaves, cont.
Bipinnate Compound Trifoliate
A compound pinnate leaf.
The leaflets of a pinnate leaf
are themselves compound.
Three leaflets. The leaflets of a trifoliate
leaf appear to be attached to a single
location but maybe a reduced pinnate
compound leaf.

14. Some Leaf Shapes: Ovate: egg-shaped, about twice as
long as it is wide, with the
widest part below the center
Elliptical: a narrow oval with the
widest part in the middle
of the leaf
Linear: very long and narrow, slightly
wider at the lower half
Obovate: egg-shaped, with the
widest part of the leaf
above the center
Obcordate: heart-shaped leaf attached
at the narrow end (the
opposite of cordate)

15. Leaf Margins Entire: not toothed or notched
Doubly Serrate: forward-facing teeth
that have smaller teeth
Serrulate: margins with small
forward-facing teeth
Serrate: forward-facing
teeth
Crenate: rounded teeth
perpendicular to
the margin

16. Leaf Margins, cont. Incised: cut by sharp, irregular incisions
Dentate: teeth pointing
perpendicular
to the margin of
the leaf
Sinuate: with a strongly
wavy margin
Lobed: margins with rounded
teeth nearly halfway to
the midrib
Undulate: margins wavy,
up and down

17. Leaf Tips Acuminate: Terminating into a long drawn out point.
Acute: Tip with sides having
an angle of less than
90 degrees.
Truncate: Cut off flat at the tip,
may sometimes be
slightly indented.
Obcordate: Heart-shaped tip.

18. Leaf Tips, cont. Emarginate: With a small notch at the apex.
Mucronate: Tipped with a short,
sharp point.
Obtuse: Sides with an
angle greater than
90 degrees
Rounded: Apex rounded.

19. Leaf Bases Cuneate: narrow wedge shaped Auriculate: ear lobe like base
Rounded: round base

20. Leaf Bases, cont. Cordate: heart shaped Truncate: cut off at the base
Oblique: unequal base sides

21. Conifers

22. Needle Types Needles in bundles or clusters
Two or more needles joined at base
Ex. White pine, jack pine, larch

23. Needle Types Needles in Singles Each needle growing singly on a twig
Ex. Douglas fur, hemlock, blue spruce

24. Needle Types Overlapping scales
Leaves shaped like overlapping plates (like fish scales)
Ex. Juniper, cedar, cypress