SALVINIA MOLESTA (SALVINIACEAE), NEWTOTEXASANDLOUISIANA COLETTEC.JACONO UnitedStatesGeologicalSurvey NW 7920 listSt. Gainesville. FL52635, U.S.A. Initiallydiscoveredataschoolyarddemonstrationpondinsoutheastern Texas,theFederalnoxiousweedSalviniamolestaMitchellhasrecentlybeen found inabundanceatToledoBend Reservoir.This75,300haimpound- mentoftheSabineRiverformsa 145kmborderbetweenTexasandLoui- sianaandisapopularbassfishinglake. NativetoasmallregionofsoutheasternBrazil(Forno 1983),S. molesta hasdominatedwaterbodiesoveranexpansiverangeincludingregionsof Africa,Asia,AustraliaandtheSouthPacific(JMitchell1972;Forno&Harley 1979). Vegetativereproductionandrapidgrowth ratescontributetothe invasivenessofthisplant,typicallyresultingindensesurfacematsthatcover openwater,degradeaquatichabitat,andconstraintheuseofreservoirsand waterways(Mitchell &Tur 1975;Thomas&Room 1986). Untilnow,S. molestahasbeensuccessfullyinterceptedatnurseries,botanicalgardens,and ataprivatepond(Myers 1982;Johnson 1995),precludingnaturalization intheUnitedStates.Likelysourcesfortheintroductionarelocalnurseries founddistributingthespeciesasanornamentalwatergardenplant(Rhandy Helton,TexasParksandWildlifeDepartment,personalcommunication). This is thesecondSalviniaspecies introduced to thesestates. Salvmia minimawasfirstreportedfromLouisianain 1980(Landry 1981)andfrom Texasin1993(Hatch1995).Itsdistributionhasincreasedextensivelysince thesereports(Montz 1989).Thetwospeciesarereadilydistinguishedby themulticeUularhairsonthetipperfrondsurface.Theapexofeachhairis dividedintofourbranches.InS.molesta,thetipsofthebranchesarejoined toform acage-likestructure,whileinS. minima,branchesarespreading andfreeatthetips.LeafhairfeaturesmaybeviewedwithalOXlensand canbeusedbybiologistsforearlyfielddetection. Thisreportdocumentsanintroductionthatconstitutesaseriousthreat toaquaticsystemsthroughoutthesouthernUnitedStates.Salviniamolesta hasbeenfoundabovethehighwaterlevelatpublicrampsandroadsalong ToledoBend Reservoir, likelydraggedtherebyboattrailers,knownvec- torsforoverlandspread(MillerandWilson 1989). SioA18(3):927-92S. 1999 928 SiDAl8(3) VoiulicTspecimens:U.S.A.TEXAS.HarrisCo.:Ilousrt)!!,wetlanddemoiistiiirionpond orRoberrBrownint;FdemencarySchool,formingdensesurfacecover,apicularesporocarps inanelongatedcymosesystem,4May1998,RonaldK.Jones(FLAS,PIHG,TARS).LOUI- SIANA.SabineParish:Many,ToledoBendReservoir,abtmdantincovesandshallows, apicLilart-sporocarpsinanelongatedcymosesystem,30Nov1998,/(/wt.iM.liyck(I'LAS). ACKNOWLl'DCiMRN'IS Theauthorgratefullyacknowledgesas.sistanceinidentificationfromNancy Code,WendyForno,andDavidMitchell. Rr,FF.RI',NC;ES Forno,I.W.198S.Nativedistribntiono{t\\vStilviiihici//i7c//Li!jcomplexandkeystospe- ciesidentiHcation.Aqtiat.Bot. 17:71-83- Forno,I.W.andK.L.S.11ai<li;y.1979.Theoccnrrenceo\'S,ilvniijmokstamBrazil.Aciiiat. Bot.6:185-187. FiATCii,S.L. 1995.Scilrniijiiiniinui(Salviniaceae),newtoTexas.Sida16:595. Johnson,B. 1995.CiiantsalviniafoundinSouthCarolina.Aquatics17:22, Landkv,Cj.P. 1981.ScilvinutmininidnewtoLouisiana.Amer.FernJ.68:95. iVIiiiJ'H,1.1..and(;.G.Wii.sON.1989.IManagemencoiSalviniaintheNorthernTerritory.J. Acjuat.PlantiManage.27:40-46. MiTcini.L,D.S. 1972.TheKaribaweed:Sc/liiiiumokitd.Brit.FernGaz. 10:251-252. Mti(iii:i,i,,D.S.andN.M.Tun. 1975.Therateofgrowtho'iScilviuuimoksta{S.cuiruiihihi auct.)mlaboratoryandnaturalconditions.J.Appl.Fcol. 12:213-225. MonAtt]/u,afGic.NP.ant19C8o9n.trDoilstRreibsteiatricohnPairSo.g/lrvanmii,ci4-)n1ni7iiNiuoivienmLboueirsi1a9n8a8.,PWroecs.t23P'a"'lmAnBneuaaclh,MFeleotriidnag, Misc.PaperA-89-1,U.S.Army(;()rpsofLngineers,Vicksburg,MS,pp.312-316. Myfks,F.D.1982.Memolostateandterritoryagriculturalregulatoryofficials.U.S.Dept. ofAgriculture,PlantProtectionantlQuarantine,DA#82-12. TilOMAS,P.A.andPM.Room.1986.Taxonomyandcontroloi'Sa/r/i/zc////o/n/a.Nature320: 581-584.