Potamogeton 
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                            Potamogeton X absconditus 
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                            Potamogeton X aemulans 
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                            Potamogeton alpinus 
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                            Potamogeton amplifolius 
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                            Potamogeton X argutulus 
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                            Potamogeton berchtoldii 
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                            Potamogeton bicupulatus 
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                            Potamogeton clystocarpus 
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                            Potamogeton X cognatus 
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                            Potamogeton confervoides 
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                            Potamogeton crispus 
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                            Potamogeton diversifolius 
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                            Potamogeton epihydrus 
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                            Potamogeton X faxonii 
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                            Potamogeton floridanus 
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                            Potamogeton foliosus 
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                            Potamogeton friesii 
                         | 
                        
                             
                            Potamogeton gramineus 
                         | 
                        
                             
                            Potamogeton X griffithii 
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                            Potamogeton groenlandicus 
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                            Potamogeton X hagstroemii 
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                            Potamogeton X haynesii 
                         | 
                        
                             
                            Potamogeton hillii 
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                            Potamogeton illinoensis 
                         | 
                        
                             
                            Potamogeton X luxurians 
                         | 
                        
                             
                            Potamogeton methyensis 
                         | 
                        
                             
                            Potamogeton X mirabilis 
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                            Potamogeton X mysticus 
                         | 
                        
                             
                            Potamogeton natans 
                         | 
                        
                             
                            Potamogeton X nericus 
                         | 
                        
                             
                            Potamogeton X nitens 
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                            Potamogeton nodosus 
                         | 
                        
                             
                            Potamogeton oakesianus 
                         | 
                        
                             
                            Potamogeton oblongus 
                         | 
                        
                             
                            Potamogeton obtusifolius 
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                            Potamogeton X ogdenii 
                         | 
                        
                             
                            Potamogeton perfoliatus 
                         | 
                        
                             
                            Potamogeton praelongus 
                         | 
                        
                             
                            Potamogeton X prussicus 
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                            Potamogeton pulcher 
                         | 
                        
                             
                            Potamogeton pusillus 
                         | 
                        
                             
                            Potamogeton X rectifolius 
                         | 
                        
                             
                            Potamogeton richardsonii 
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                            Potamogeton robbinsii 
                         | 
                        
                             
                            Potamogeton X saxonicus 
                         | 
                        
                             
                            Potamogeton X schreberi 
                         | 
                        
                             
                            Potamogeton X sparganiifolius 
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                            Potamogeton X spathuliformis 
                         | 
                        
                             
                            Potamogeton spirillus 
                         | 
                        
                             
                            Potamogeton strictifolius 
                         | 
                        
                             
                            Potamogeton X subdentatus 
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                            Potamogeton X subobtusus 
                         | 
                        
                             
                            Potamogeton X subsessilis 
                         | 
                        
                             
                            Potamogeton subsibiricus 
                         | 
                        
                             
                            Potamogeton tennesseensis 
                         | 
            
            
                        
                             
                            Potamogeton tricarinatus 
                         | 
                        
                             
                            Potamogeton X undulatus 
                         | 
                        
                             
                            Potamogeton vaseyi 
                         | 
                        
                             
                            Potamogeton X versicolor 
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                            Potamogeton zosteriformis 
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