CONTENTS 



Page 



PREFACE iii 



SUBMERSED AQUATIC WEEDS 1 



Sago pondweed [Potamogeton pectinatus) 2 



Leafy pondweed {Potamogeton foliosus) 4 



American pondweed {Potamogeton nodosus) 6 



Curlyleaf pondweed {Potamogeton crispus) 8 

 Richardson pondweed {Potamogeton 



Richardson//) 10 



Whitestem pondweed {Potamogeton praelongus) 12 



Giant pondweed {Potamogeton vag/natus) 14 



Horned pondweed {Zann/chell/a palustr/s) 16 



Waterweed {Elodea canadens/s) 18 



Hydrilla {Hydr/Ila vert/c/Uata) 20 



Waterbuttercup {Ranunculus spp.) 22 



Coontail ( Ceratophyllum demersum ) 24 



Watermilfoil (A/Kr/op/?7//f/i77spp.) 26 



Eurasian watermilfoil {Myr/ophyllum sp/catum) 28 



Waterplantain {Al/sma gram/neum) 30 



Holly-leaved waternymph {Najas manna) 32 



Waterstargrass {Heterantbera dub/a) 34 



Watercress ( Rad/cula Nasturt/um-aquat/cum ) 36 



True moss {Bryopbyta) 38 



ALGAE 41 



Filamentous green algae 42 



Blue-green algae 44 



Stoneworts {Cbara spp. and N/teJIa spp.) 46 



FLOATING AQUATIC WEEDS 49 



Duckweed ( Z/e/77775 spp. and Wolff /a spp.) 50 



Waterhyacinth {E/cborn/a crass/pes) 52 



Alligatorweed {Alternantbera pb/loxero/des) 54 



