Certified Professional Horticulturist (CPH) Practice Exam

What defining feature helps distinguish between ornamental trees and shrubs?

1. Height

2. Leaf shape

3. Root system

4. Flower color

The correct answer is: Height

The defining feature that helps distinguish between ornamental trees and shrubs is primarily height. Trees are generally characterized by having a single trunk that elevates them to a greater height than shrubs, which tend to have multiple stems or branches that create a bushier appearance at a lower height. This height differentiation is key because it contributes to their roles in landscapes; trees often provide shade and vertical elements, while shrubs are typically used for ground cover, borders, or privacy screens. The other characteristics, such as leaf shape, root system, and flower color, can vary widely among both trees and shrubs and are not consistently reliable indicators for classification between the two groups.