Leaf Classifications
Leaves are the part of a tree most commonly used to identify it. Variations in leaves are used to divide trees into groups. The following characteristics are most often considered:
• Leaf type: simple (single leaf), compound (leaves grouped on a single branch), or needle
• Compound leaf arrangements: alternate, opposite or in pairs, whorl or spiral, basal or in bundles, in groups of a specific number, or double compound (compound groups arranged in a larger compound grouping)
• Leaf margins: entire or smooth, lobed, revolute, regularly toothed, irregularly toothed, fine toothed, coarse-toothed or serrated, wavy or scalloped
• Leaf shape: linear, oblong, oval, ovate, cordate (heart shaped), lobed, deltoid (triangular), orbicular (round), 4-sided needle, flattened needle
• Needle Arrangements: single, double, bundles of five, clusters of more than five, flat, scale- like
Leaves are the part of a tree most commonly used to identify it. Variations in leaves are used to divide trees into groups. The following characteristics are most often considered:
• Leaf type: simple (single leaf), compound (leaves grouped on a single branch), or needle
• Compound leaf arrangements: alternate, opposite or in pairs, whorl or spiral, basal or in bundles, in groups of a specific number, or double compound (compound groups arranged in a larger compound grouping)
• Leaf margins: entire or smooth, lobed, revolute, regularly toothed, irregularly toothed, fine toothed, coarse-toothed or serrated, wavy or scalloped
• Leaf shape: linear, oblong, oval, ovate, cordate (heart shaped), lobed, deltoid (triangular), orbicular (round), 4-sided needle, flattened needle
• Needle Arrangements: single, double, bundles of five, clusters of more than five, flat, scale- like
Needle Arrangements
Parts of a leaf
1. apex
2. margin
3. base
4. petiole
5. mid-rib
6. lateral vein
2. margin
3. base
4. petiole
5. mid-rib
6. lateral vein