Orange County NC Website
Browse       Search
7 <br /> NR C S U.S. Department of Agriculture <br /> Natural Resources Conservation Service <br /> 344 Merrow Road,Suite A * Tolland, Connecticut 06084-3917 * (860)871-4011 * www.ct.nres.usda.gov <br /> . . <br /> Hydrilla <br /> Hydrilla verticillata (L.f.) Royle <br /> Alternate Latin Names: Elodea verticillata(L.f.)F.Muell.;Serpicula verticillata L.£;Hydrilla lithuanica(Andrz. <br /> ex Besser)Dandy Alternate Common Name: Indian Star-vine;Waterthyme <br /> -perennial(occasionally annual)water plant with leaves whorled on underwater stems <br /> -middle and upper stem whorls have mostly 5 to 8 leaves(occasionally 3 - 12 leaves per whorl) <br /> -leaf edges are finely toothed; teeth visible to the naked eye(look closely!) <br /> -leaves less than 1" long(1/4"to a little over 3/4" long); narrow(about 1/8"wide) <br /> -has both subterranean turions("tubers")and stem turions(described below) <br /> -plants may be rooted(in as much as 30 feet of water)or may be floating fragments <br /> -flowers tiny,floating;petals translucent, less than 1/4" long; male flowers detach from plant <br /> With its narrow,whorled, leaves,Hydrilla may be confused with native Water-weeds (Elodea Michx.). Native <br /> Water-weeds typically have 3 leaves per whorl while Hydrilla typically has 5-8 leaves per whorl in its middle and <br /> upper stem. In contrast to Hydrilla's toothed leaves,the teeth on the native Water-weed leaf margins are not visible <br /> to the naked eye. <br /> Subterranean turions (also called"tubers")grow in the soil beneath the water at the tips of"roots"(underground <br /> rhizomes or rooted stolons spreading over the sand or mud). The "tubers"are less than 1/2" long and resemble <br /> miniature, whitish to brown-black Jerusalem artichokes; and remain viable underground for many years. Stem <br /> turions are 1/4" long,tough, green, deciduous,bud-like shoots found along the stem. Stem turions remain viable <br /> less than a year. The native Water-weeds have dark green, leafy turions at the stem tips, but no underground <br /> "tubers". <br /> photo by -_ r <br /> Dave Spencer, photo by Dave Spence <br /> USDA-ARS <br /> f ' <br /> 4J <br /> ry <br /> k <br /> r <br /> e' <br /> �s <br /> Text and photos by: Charlotte Pyle,October 2002 <br /> Helpful review provided by:Lillian Willis <br /> The U S Department of Agriculture(USDA)prohibits discrimination in all its programs and activities on the basis of race,color,national origin,sex,religion,age,disability,political beliefs,sexual orientation,or marital <br /> or family status(Not all prohibited bases apply to all programs)Persons with disabilities who require alternative means for communication of program information(Braille,large print,audiotape,etc)should contact <br /> USDA's TARGET Center at 202-720-2600(voice and TDD) To file a complaint of discrimination,write USDA,Director,Office of Civil Rights,Room 326-W,Whitten Building,1400 Independence Avenue,SW, <br /> Washington,DC 20250-9410 or call(202)720-5964(voice and TDD) USDA is an equal opportunity provider and employer. <br /> 11/2002 <br />