Pipers Pond in Limerick is now covered by the invasive plant Hydrilla (Hydrilla Verticillata) over 60 to 70 percent of its surface. Two years ago there was no indication of this plant. Now canoeing or motoring through the dense growth would be impossible.
Hydrilta verticillata
Habitat: Emergent to Submersed plant community; can grow in various substrates (sand, mud or gravel).
Hydrilla is a long slender, submersed, aquatic plant with numerous branches. Its small, pointed leaves are serrated on the edges with a reddish midrib that often has sharp spines on the underside. The leaves are arranged in whorls of 4-8. Tiny white flowers grow on long stalks from the leaf axils. Hydrilla produces vegetative buds or turions at the leaf axils. Quarter to half inch, cream to yellowish colored tubers form on the roots of the plant.
Hydrilla is present in Connecticut and Massachusetts
Myriophyllum spicatum
Habitat: Floating-leaved to Submersed plant community; thrives in areas with soft sediments, but can grow in other substrates (sand, mud or gravel).
Eurasian Water Milfoil is a submersed, aquatic plant with feather-like divided leaves. Leaves are arranged in densely packed whorls of 3-6 around the stem, with 12 or more pairs of thread-like leaflets on each leaf. Flowers occur in the axils of bracts, arranged in whorls around a slender spike that emerges from the surface of the water mid to late summer. This flowering spike is important for distinguishing Eurasian from Variable Milfoil. The flowers of Eurasian Milfoil are larger than the bracts, whereas the flowers of Variable Milfoil are smaller than the bracts. Eurasian Milfoil bracts have smooth margins, whereas those of Variable Milfoil are serrated, or deeply toothed.
Eurasian Water Milfoil is present in New Hampshire, Vermont, Massachusetts, Connecticut, New York, and several Canadian Provinces.