| 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                F. S. Collins 5194 | 
                                22 Apr 1905 | 
                                United States of America | 
                                Massachusetts | 
                                Barnstable Co. Woods Hole | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
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                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                M. H. Bray s.n. | 
                                May 1882 | 
                                United States of America | 
                                Massachusetts | 
                                Essex Co. Magnolia | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                F. S. Collins s.n. | 
                                Jul 1903 | 
                                United States of America | 
                                Maine | 
                                Cumberland Co. South Harpswell, floating | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                J. R. Anderson 642 | 
                                16 Feb 1897 | 
                                Canada | 
                                British Columbia | 
                                Beacon Hill Beach | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
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                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                F. S. Collins s.n. | 
                                May 1899 | 
                                United States of America | 
                                Massachusetts | 
                                Suffolk Co. Revere Beach | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                F. S. Collins 1635 | 
                                11 May 1890 | 
                                United States of America | 
                                Massachusetts | 
                                Suffolk Co. Revere Beach | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                Collector unknown 507 | 
                                11 Aug 1971 | 
                                United States of America | 
                                Massachusetts | 
                                Suffolk Co. Revere Beach | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
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                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                Collector unknown s.n. | 
                                08 Jun 1879 | 
                                United States of America | 
                                Massachusetts | 
                                Suffolk Co. Revere Beach | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
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                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                F. S. Collins 511 | 
                                Apr 1890 | 
                                United States of America | 
                                Massachusetts | 
                                Suffolk Co. Revere Beach | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                Illegible collector name s.n. | 
                                01 Jun 1899 | 
                                United States of America | 
                                Rhode Island | 
                                Newport Co. Easton's Point | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                W. C. Simmons s.n. | 
                                16 Apr 1900 | 
                                United States of America | 
                                Rhode Island | 
                                Newport Co. | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                W. C. Simmons s.n. | 
                                Apr 1898 | 
                                United States of America | 
                                Rhode Island | 
                                Newport Co. | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                M. A. Howe 1790 | 
                                02 Apr 1903 | 
                                United States of America | 
                                New York | 
                                Hunter's Island [=Hunter Island]. | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
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                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                W. C. Simmons s.n. | 
                                — | 
                                United States of America | 
                                Rhode Island | 
                                Newport Co. | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                W. C. Simmons s.n. | 
                                — | 
                                United States of America | 
                                Rhode Island | 
                                Newport Co. | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
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                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                — | 
                                — | 
                                — | 
                                — | 
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                                — | 
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                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                — | 
                                — | 
                                — | 
                                — | 
                                 | 
                                — | 
                                 | 
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                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                F. S. Collins s.n. | 
                                30 May 1905 | 
                                United States of America | 
                                Massachusetts | 
                                Plymouth Co. | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                W. C. Simmons s.n. | 
                                29 Apr 1911 | 
                                United States of America | 
                                Rhode Island | 
                                Newport Co. Conanicut | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
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                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                Collector unknown s.n. | 
                                29 Apr 1901 | 
                                United States of America | 
                                Rhode Island | 
                                Newport Co. Conanicut | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                W. C. Simmons s.n. | 
                                Mar 1898 | 
                                United States of America | 
                                Rhode Island | 
                                Newport Co. Conanicut, east shore | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                I. Holden s.n. | 
                                s.d. | 
                                United States of America | 
                                Connecticut | 
                                Fairfield Co. below low water… | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                I. Holden 1348 | 
                                — | 
                                United States of America | 
                                Connecticut | 
                                Fairfield Co. Bridgeport | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
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                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                F. S. Collins s.n. | 
                                05 May 1890 | 
                                United States of America | 
                                Massachusetts | 
                                Suffolk Co. Revere Beach | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
                                                                  | 
                                
                                    
                                 | 
                            
                       
                        
                            
                            
                                | 
                                    Antithamnion americanum (Harv.) Kjellm.
                                 | 
                                W. A. Setchell 41 | 
                                17 May 1890 | 
                                United States of America | 
                                Massachusetts | 
                                Suffolk Co. Revere Beach | 
                                — | 
                                 | 
                                 | 
                                
                                                                      
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                                 |