51. This most common floating weed in Ohio ponds looks like a dense mat of hairlike fibers, growing on the pond bottom and on submerged vegetation.
A. Waterweed
B. Floating-Leaf pondweed
C. Water milfoil
D. Filamentous algae
52. This weed is commonly called muskgrass or stonewort. It grows in clumps in shallow areas and has a musky or skunky odor when crushed.
A. Chara
B. Coontail
C. Duckweed
D. Water milfoil
53. The following weed usually has three-lobed leaves with rootless that hang down in the water. It is usually found in sheltered ponds that have little wind action, covering the pond with a green blanket.
A. Brushy pondweed
B. Waterweed
C. Duckweed
D. Algae
54. Emergent weeds, growing along the margin of the pond and shallow waters, have stems protruding above the water. Examples are:
A. Cattails, leafy pondweed, waterweed and coontail
B. Cattails, bulrushes, arrowhead and spatterdock
C. Cattails, water milfoil and coontail
D. Cattails, brushy pondweed and muskgrass
55. Thriving in clear, calm, shallow water, these plants grow below the surface. They may be loosely or firmly rooted or suspended clusters. Some may blossom on a stem that extends above the surface.
A. Filamentous algae
B. Submerged weeds
C. Floating weeds
D. Emergent weeds
56. This persistent plant reproduces by plant fragments, spores and cell division. Common forms range from green and slimy to cottony to a very coarse texture.
A. Watermeal
B. Coontail
C. Pondweeds
D. Filamentous Algae
57. Coontail, water milfoil, water weeds and naiads are commonly found
A. Emergent weeds
B. Submerged weeds
C. Algaes
D. Floating weeds
58. Match the following descriptions:
| Algae | A. Simple plants without true roots, leaves or flowers. |
| Emergent Plants | B. Plants living beneath the surface, usually rooted in bottom sediments. |
| Submerged Plants | C. Flattened or boat shaped clusters of leaves with roots extending into the water for nutrients. |
| Rooted Floating Plants | D. Rooted in water 1 to 5 feet depth, plants consist of floating or erect leaves extending from rhizomes, often having flowers. |
| Free Floating Plants | E. Plants extend above the water, rooted in 1 to 3 feet of water |
51. Correct Answer: D, OPM
Explanation: The most common type of floating weed in Ohio ponds is filamentous algae ("moss" or "pond scum"). This weed, which looks like a dense mat of hairlike fibers, starts to grow on the pond bottom and on submerged vegetation. It floats to the surface, often covering large areas of the pond. Most species of this plant group can be controlled with very low concentrations of copper sulfate.
52. Correct Answer: A, OPM
Explanation: Another form of algae that grows attached to the bottom is chara. Commonly called muskgrass or stonewort. It usually grows in clumps in shallower areas. When crushed it may have a musky or skunky odor.
53. Correct Answer: C, OPM
Explanation: Another group of weeds occasionally occurs in Ohio ponds, especially very sheltered ponds that have little wind action on the surface. These weeds are duckweed and watermeal. Although they float freely on the water surface, they are treated as emergent weeds. Duckweed has tiny, usually three-lobed leaves with rootless that hang down in the water. Watermeal appears as minute green grains floating on the water. Dense populations of these weeds often form a green blanket on the water surface.
54. Correct Answer: B, OPM
Explanation: This group of weeds includes those growing along the margin of the pond as well as in other shallow waters. Their stems and leaves protrude above the water surface. Examples are cattails, bulrushes, arrowhead and spatterdock. Some, especially cattails, may spread rapidly by growth of underwater stems and may reach depths of three feet or more.
55. Correct Answer: B, OPM
Explanation: Many water weeds grow below the surface of the water. Some are loosely rooted and others are firmly rooted. Still others appear to be suspended fragments or clusters. Some have a few leaves that float on the surface, while many blossom and produce seed on a stem that extends above the water surface. This general group is referred to as submerged weeds. They thrive in clear, calm, shallow waters.
56. Correct Answer: D, A-3
Explanation: Filamentous algae is often a persistent problem because it reproduces by plant fragments, spores and cell division. There are many species of filamentous algae and microscopic examination is usually required to make an exact identification. However, some of the more common forms can be distinguished by their texture. Spirogyra is bright green and slimy to the touch; Cladophora has a cottony feel, and Pithophora is often referred to as "horse hair" algae because its coarse texture resembles that of horse hair and it may feel like steel wool.
57. Correct Answer: B, OPM
Explanation: Many species of submerged weeds are found in Ohio ponds. The common kinds include the large family of pondweeds: coontail, water milfoil, water weeds, and naiads.
58. Correct Answers: ILL
A Algae
E Emergent Plants
B Submerged Plants
D Rooted Floating Plants
C Free Floating Plants