By Leaf Type:
- Deciduous Trees
- Coniferous Trees
By Seed Type:
- Gymnosperms
- Angiosperms
By Growth Type:
- Broadleaf Trees
- Needle-leaved Trees
- Columnar Trees
- Weeping Trees
- Pyramidal Trees
By Ecological Role:
- Pioneer Trees
- Climax Trees
By Wood Type:
- Hardwoods
- Softwoods
By Flowering Characteristics:
- Monoecious
- Dioecious
By Habitat:
- Tropical Rainforest Trees
- Desert Trees
- Boreal Forest Trees
By Use:
- Timber Trees
- Fruit Trees
- Ornamental Trees
