Question

Which one is not a floating aquatic weed

• A. Sagitaria
• B. Pistia
• C. Azolla
• D. Ipomoea

Hint:

Arrowhead leaves projecting well above the water surface indicate an emergent weed.
This is a key characteristic of Sagittaria, separating it from free-floating or floating-leaved weeds.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Aquatic weeds are classified based on their growth habits and positioning in the water body into categories like free-floating, emergent, submerged, and marginal weeds.

Step 2: Detailed Explanation:
Let us evaluate the vegetative habits of the given options:
1. Pistia (Water lettuce) is a free-floating aquatic weed that floats on the surface with roots suspended.
2. Azolla (Water fern) is a small, free-floating aquatic fern.
3. Ipomoea aquatica (Water spinach) can grow as a floating aquatic plant or along marginal areas.
4. Sagittaria (Arrowhead) is a rooted emergent weed.
Its roots are firmly anchored in the pond bottom mud, and its leaves project above the water surface.
Therefore, Sagittaria is not categorized as a floating weed.

Step 3: Final Answer:
The correct option is (A) Sagitaria.