Understanding Good Weeds Vs. Bad Weeds
For the Chautauqua Watershed Conservancy
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7/8/2007 - Weeds in the garden, weeds in the lake, weeds in the lawn — those of us who are fairly vigorous gardeners can get a little crazy about the darn things. They seem to always be where they are not wanted. In fact, an education colleague of mine explained the difference between soil and dirt in a similar context. Soil is a valuable, needed resource that provides plants and the food we need. Dirt is misplaced soil, like on the kitchen floor. I've used the same analogy for weeds; they are misplaced plants. Plants are a valuable, needed resource, while weeds are plants that are in an unwanted place.
The weeds in the lake have acquired considerable attention and press coverage. Among them, know that there are both ''good weeds'' and ''bad weeds.'' This oversimplified division requires the further understanding that aquatic plants come in three main categories. Emergent plants show some of their growth above the surface of the water like cattails and rice. Floating plants lay on the surface of the water like lotus and pond lilies. Submersed plants, also called submersed aquatic vegetation, grow almost entirely underwater. It is this last category that is sometimes referred to as ''seaweed,'' often with a negative adjective included. An additional division is applied to plants, whether they are native or exotic. Native means the plant originated in the area. Exotic means it was brought to the United States.
As its name indicates, Eurasian water milfoil was brought from Europe and Asia in the late 1800's where it was used as an aquarium plant. Its scientific name, Myriophyllum spicatum which means many spiked leaves, clearly describes its appearance. Open any single leaf and you will count more than 14 pairs of pointed leaflets with clusters of leaves called whorls piled closely together on the stalk. This leaf density, plus the plant's ability to grow quickly in cool water in the spring, cause it to shade any slower growing native plants. Its longer growing season (it can flower in both spring and fall), re-rooting ability and density have earned it one additional adjective — invasive. This is one bad weed.
Curly-leaf pondweed, Potamogeton crispus, is another exotic submerged plant. This plant reproduces from buds, called turions, and has been known to produce 1600 turions per square meter with a 60 to 80 percent germination rate. Even though this plant has more delicate leaves, it roots easily on soft sediment and tolerates low sunlight and cloudy water. These abilities would earn it an ''invasive bad weed'' title, only this dominant plant dies back to dormancy in mid-July due to warmer water temperatures. If weeds are unwanted plants, these plants are very cooperative and get out of our way during the warm summer months.
Let's now look below the surface at an amazing underwater forest filled with ''good weeds.'' Here that term ''weed'' just does not apply, because this ecosystem is brimming with a variety of delicate native plants that are performing their roles to perfection. Other than the water-thread pondweed and the Eurasian water milfoil, the small collection of plants seen in the photo were gathered by two rake tosses into Whitney Bay on Chautauqua Lake. The Small pondweed, Potamogeton pusillus (Latin for ''very small'), is fairly tall with slender leaves. It is native and is a food source for ducks and geese. It is also a food source and cover for fish. Elodea, Elodea Canadensis, has whorls of three leaves that are fairly crowded on the stem. This native plant provides excellent shelter and grazing for fish. It is also a food source for muskrats and waterfowl and additionally is a habitat for many invertebrates. Coontail, Ceratophyllum demersum, is often misidentified as water milfoil. It has stiff leaves arranged in whorls from five to 12 at a time. The whorls are more closely spaced at the tips of the plant giving its raccoon-tail appearance. This more rugged structure makes this native plant vital to the underwater forest. It provides habitat during the winter for invertebrates and fish when many other plants are reduced to roots. In the warmer months it provides good shelter and food for fish along with a host of ducks including the beautiful Wood Duck and teals.
Then there is the ''star'' of this small collection, star duckweed, Lemna triscula. Its identification was made through the assistance of Robert Johnson, aquatic plant specialist from Cornell University Research Ponds. Star duckweed is not just good; it is amazing. Its delicate leaves are spring green in color and it is here that the active cells contain twice as much protein, fat, nitrogen and phosphorus as other vascular plants. This occurs because there is little structural fiber or root system; each leaf absorbs nutrients directly from the water. Thus, this wonderful plant has a high nutrient value for fish and waterfowl and is good habitat for aquatic invertebrates. Its high-nutrient value has seen this plant used as feed for cattle and pigs in Africa, India and Southeast Asia. It has also been used to remove nutrients from sewage effluent. This diminutive, gentle, native plant could be one of the most hard-working giants of our underwater forest.
Appreciating the beauty of this underwater forest can be added to our list of amazing discoveries made right here in the Chautauqua Watershed. Understanding the multiple roles of the submersed plants in the ecosystem enhances that appreciation. So when we hear ''weeds,'' there are many underwater plants that are far better than good — their contributions to the ecosystem are stellar.
The Chautauqua Watershed Conservancy is a local, not-for-profit grass roots land conservation, watershed education and advocacy organization. Its mission is to preserve and enhance the ecology, water quality and scenic beauty of the lakes, streams and watersheds of the Chautauqua region with 1,400 individuals, families, businesses and organizations as members. Its 2007 membership drive is underway. Donations of cash, securities and real estate may be tax deductible. For membership information call 664-2166 or visit the CWC online at www.chautauquawatershed.org.
The weeds in the lake have acquired considerable attention and press coverage. Among them, know that there are both ''good weeds'' and ''bad weeds.'' This oversimplified division requires the further understanding that aquatic plants come in three main categories. Emergent plants show some of their growth above the surface of the water like cattails and rice. Floating plants lay on the surface of the water like lotus and pond lilies. Submersed plants, also called submersed aquatic vegetation, grow almost entirely underwater. It is this last category that is sometimes referred to as ''seaweed,'' often with a negative adjective included. An additional division is applied to plants, whether they are native or exotic. Native means the plant originated in the area. Exotic means it was brought to the United States.
As its name indicates, Eurasian water milfoil was brought from Europe and Asia in the late 1800's where it was used as an aquarium plant. Its scientific name, Myriophyllum spicatum which means many spiked leaves, clearly describes its appearance. Open any single leaf and you will count more than 14 pairs of pointed leaflets with clusters of leaves called whorls piled closely together on the stalk. This leaf density, plus the plant's ability to grow quickly in cool water in the spring, cause it to shade any slower growing native plants. Its longer growing season (it can flower in both spring and fall), re-rooting ability and density have earned it one additional adjective — invasive. This is one bad weed.
Curly-leaf pondweed, Potamogeton crispus, is another exotic submerged plant. This plant reproduces from buds, called turions, and has been known to produce 1600 turions per square meter with a 60 to 80 percent germination rate. Even though this plant has more delicate leaves, it roots easily on soft sediment and tolerates low sunlight and cloudy water. These abilities would earn it an ''invasive bad weed'' title, only this dominant plant dies back to dormancy in mid-July due to warmer water temperatures. If weeds are unwanted plants, these plants are very cooperative and get out of our way during the warm summer months.
Let's now look below the surface at an amazing underwater forest filled with ''good weeds.'' Here that term ''weed'' just does not apply, because this ecosystem is brimming with a variety of delicate native plants that are performing their roles to perfection. Other than the water-thread pondweed and the Eurasian water milfoil, the small collection of plants seen in the photo were gathered by two rake tosses into Whitney Bay on Chautauqua Lake. The Small pondweed, Potamogeton pusillus (Latin for ''very small'), is fairly tall with slender leaves. It is native and is a food source for ducks and geese. It is also a food source and cover for fish. Elodea, Elodea Canadensis, has whorls of three leaves that are fairly crowded on the stem. This native plant provides excellent shelter and grazing for fish. It is also a food source for muskrats and waterfowl and additionally is a habitat for many invertebrates. Coontail, Ceratophyllum demersum, is often misidentified as water milfoil. It has stiff leaves arranged in whorls from five to 12 at a time. The whorls are more closely spaced at the tips of the plant giving its raccoon-tail appearance. This more rugged structure makes this native plant vital to the underwater forest. It provides habitat during the winter for invertebrates and fish when many other plants are reduced to roots. In the warmer months it provides good shelter and food for fish along with a host of ducks including the beautiful Wood Duck and teals.
Then there is the ''star'' of this small collection, star duckweed, Lemna triscula. Its identification was made through the assistance of Robert Johnson, aquatic plant specialist from Cornell University Research Ponds. Star duckweed is not just good; it is amazing. Its delicate leaves are spring green in color and it is here that the active cells contain twice as much protein, fat, nitrogen and phosphorus as other vascular plants. This occurs because there is little structural fiber or root system; each leaf absorbs nutrients directly from the water. Thus, this wonderful plant has a high nutrient value for fish and waterfowl and is good habitat for aquatic invertebrates. Its high-nutrient value has seen this plant used as feed for cattle and pigs in Africa, India and Southeast Asia. It has also been used to remove nutrients from sewage effluent. This diminutive, gentle, native plant could be one of the most hard-working giants of our underwater forest.
Appreciating the beauty of this underwater forest can be added to our list of amazing discoveries made right here in the Chautauqua Watershed. Understanding the multiple roles of the submersed plants in the ecosystem enhances that appreciation. So when we hear ''weeds,'' there are many underwater plants that are far better than good — their contributions to the ecosystem are stellar.
The Chautauqua Watershed Conservancy is a local, not-for-profit grass roots land conservation, watershed education and advocacy organization. Its mission is to preserve and enhance the ecology, water quality and scenic beauty of the lakes, streams and watersheds of the Chautauqua region with 1,400 individuals, families, businesses and organizations as members. Its 2007 membership drive is underway. Donations of cash, securities and real estate may be tax deductible. For membership information call 664-2166 or visit the CWC online at www.chautauquawatershed.org.
For more information on Chautauqua Lake Real Estate & Living visit: www.chautauqualakehomes.com
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