1. 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

2. Leaf Structure The Leaf Blade
The blade is the entire leaf unit. Sometimes this is made up of several smaller leaflets.  

3. Leaf Veins

4. Leaf Margin
The margin is the term used to describe the edge of the leaf.

5. Leaf Base
Base is the name given to the part of the blade that is closest to the stem.

6. Leaf Apex
The Apex is the tip of the leaf.

7. Petiole
The Petiole is the thin stalk that connects the leaf blade to the stem

8. Stipule
Stipules are tiny leaf-like structures that may or may not be present at the base of the petiole.

9. Petiolate and Sessile Leaves which have petioles are called Petiolate
If a leaf has no petiole it is called Sessile.

10. Seven Main Leaf Structures

11. Leaf Blade The main part of a leaf is the blade. Nine major shapes
Linear
Lanceolate
Oblong
Elliptic
Ovate Cordate
Reniform
Spatulate
Orbicular

12. Linear
Narrow, with parallel or nearly parallel side

13. Lanceolate lance shaped, longer than broad and
tapering to a point at the tip

14. Oblong
Much longer than wide, with nearly parallel sides

15. Elliptic
Shaped like an ellipse, wider at the center and tapering to equal tips

16. Ovulate
  egg-shaped, broader at the base than the tip 

17. Cordate
Heart shaped, either the leaf shape or base

18. Reniform
Kidney shaped

19. Spatulate
In the shape of a spatula or spoon

20. Orbicular
Round

21. Leaf Groupings
How leaves are grouped on stem
Simple
Compound

22. Three types of compound

25. 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.

26. Entire
Smooth no bumps

27. Toothed
Shallow bumps

28. Dentate
Pointing outward
                                                            

29. Serrate
Point to the leaf’s tip
                                                            

30. Crenate
Broad and round

31. Incised
deeply cut with sharp, irregular teeth
                                                            

32. Lobed
deep indents or sinuses

33. Sinnate
very wavy margin

34. Undulate
wavy margin, but not as wavy as a sinuate margin