What is the difference between elodea and hydrilla

In addition, we found evidence of the confusion, dating back to the s, between Canadian waterweed and western waterweed in the mid-Atlantic region of the United States. Canadian waterweed was previously reported as common and western waterweed as rare; however, our samples indicate the opposite is true.

This information indicates there is a need for investigators to anticipate the spread of hydrilla populations to northern U. Our ability to confirm distribution and pace of spread of invasive and noninvasive species will improve with increased application of molecular techniques. Molecular techniques to distinguish morphologically similar Hydrilla verticillata , Egeria densa , Elodea nuttallii , and Elodea canadensis Journal of Aquatic Plant Management.

By: Nancy B. Rybicki , Julie D. Kirshtein , and Mary A. Flowers are unisexual, arising from the leaf axil; plants are monoecious or dioecious. The flowers are small, less than 6 mm in diameter, translucent to white, on upper branches, and usually produced in the fall.

The male flowers are solitary, small, short-petioled, breaking off the stem as buds and opening explosively on the water surface. Female flowers are solitary, subsessile but with a long threadlike structure that carries the flower to the surface.. So far, in a given locality only one type of plant has been found, either monoecious or dioecious with male flowers. The range of monoecious hydrilla includes the mid-Atlantic states south to South Carolina; dioecious plants with male flowers are found elsewhere.

Hydrilla was introduced from the Old World, now abundantly naturalized in many parts of the U. Plants have attractive foliage and are planted in aquaria from which they may escape. Hydrilla is easily confused with Egeria densa Brazilian elodea or egeria and Elodea canadensis Canada elodea, waterweed.

Comparisons of whorls of leaves of these three and the key given in the description of Egeria densa emphasize their differences. Plants form large, dense populations that displace native species and impair water use. Undoubtedly, plants are spread from lake to lake by fragments attached to boat motors.

Presumably the capsules or seeds, or specialized buds and tubers turions , are dispersed by water.