Certified Professional Horticulturist (CPH) Practice Exam

How do sedges differ from grasses?

1. They have parallel veins

2. They have a fibrous root system

3. They have leaf blades that are wider than they are long

4. They have triangular stems

The correct answer is: They have triangular stems

Sedges are distinguished from grasses primarily by their stem structure; they have triangular stems, which is one of the key identifying features of the Cyperaceae family to which sedges belong. This triangular cross-section is contrasted by the round stems of most grasses in the Poaceae family. This morphological characteristic is an important identification tool for anyone studying or working with these two plant groups, as it indicates not only structural differences but also differences in growth habits and habitats where these plants thrive. The other characteristics listed, such as having parallel veins or a fibrous root system, are not exclusive to either category and can apply to both sedges and grasses. Leaf blade width relative to length is also not a definitive trait to distinguish the two, as both groups exhibit a variety of leaf forms and sizes.