| Zostera noltei | IE, VCH38 Co. Down, Greyabbey | Coslett Herbert Waddell | Watson Botanical Exchange Club Coslett Herbert Waddell | 7/9/1918 | SLBI |
| Eleogiton fluitans | IE, VCH38 Co. Down, Kircubbin | Coslett Herbert Waddell | Coslett Herbert Waddell Harold Stuart Thompson Watson Botanical Exchange Club | 7/1918 | BIRM |
| Apium inundatum | IE, VCH38 Co. Down, Kircubbin | Coslett Herbert Waddell | Watson Botanical Exchange Club Harold Stuart Thompson | 1918 | BIRM |
| Apium inundatum | IE, VCH38 Co. Down, Kircubbin | Coslett Herbert Waddell | Watson Botanical Exchange Club Harold Stuart Thompson | 1918 | BIRM |
| Scleranthus annuus | IE, VCH38 Co. Down, grey abbey | Coslett Herbert Waddell | Watson Botanical Exchange Club Coslett Herbert Waddell Harold Stuart Thompson | 2/10/1917 | BIRM |
| Polygonum aviculare | IE, VCH38 Co. Down, Ballywalter | Coslett Herbert Waddell | Watson Botanical Exchange Club Arthur Bennett Charles Edgar Salmon Coslett Herbert Waddell Edward Shearburn Marshall Harold Stuart Thompson | 21/9/1917 | BIRM |
| Polygonum aviculare var. littorale | IE, VCH38 Co. Down, Ballywalter | Coslett Herbert Waddell | Watson Botanical Exchange Club Coslett Herbert Waddell William Robert Sherrin | 21/9/1917 | SLBI |
| Atriplex | IE, VCH38 Co. Down, Ballywalter | | University of Sheffield Coslett Herbert Waddell Botanical Exchange Club of The British Isles | 9/1917 | BIRM |
| Potentilla intermedia | IE, VCH19 Co. Kildare, Grey Abbey Cultivated | Coslett Herbert Waddell | Watson Botanical Exchange Club Alfred James Wilmott Coslett Herbert Waddell Harold Stuart Thompson | 9/1917 | BIRM |
| Barbarea intermedia | IE, VCH38 Co. Down, Greyabbey | Coslett Herbert Waddell | Botanical Exchange Club of The British Isles Coslett Herbert Waddell Douglas Montague Heath Frederick Robinson | 6/1917 | BIRM |
| Polygonum arenastrum | IE, VCH38 Co. Down, grey abbey | Coslett Herbert Waddell | Watson Botanical Exchange Club Coslett Herbert Waddell William Robert Sherrin | 9/1916 | SLBI |
| Polygonum arenastrum | IE, VCH38 Co. Down, Greyabbey | Coslett Herbert Waddell | Watson Botanical Exchange Club Coslett Herbert Waddell Harold Stuart Thompson | 9/1916 | BIRM |
| Polygonum rurivagum | IE, VCH38 Co. Down, Greyabbey | Coslett Herbert Waddell | Watson Botanical Exchange Club Coslett Herbert Waddell Harold Stuart Thompson | 9/1916 | BIRM |
| Arenaria serpyllifolia | IE, VCH31 Co. Louth, Omeath | Coslett Herbert Waddell | Watson Botanical Exchange Club Charles Edgar Salmon Edward Shearburn Marshall Harold Stuart Thompson | 7/1916 | BIRM |
| Brassica rapa var. briggsii | IE, VCH37,VCH38, Warrenpoint | Coslett Herbert Waddell | Watson Botanical Exchange Club Harold Stuart Thompson | 7/1916 | BIRM |
| Linum catharticum | IE, VCH38 Co. Down, Saintfield | | Coslett Herbert Waddell | 7/1916 | GALW |
| Euphrasia nemorosa | IE, VCH38 Co. Down, Mount Stewart | Coslett Herbert Waddell | Watson Botanical Exchange Club Harold Stuart Thompson | 1916 | BIRM |
| Rosa canina x obtusifolia = R. x dumetorum | IE, VCH38 Co. Down, grey abbey | Coslett Herbert Waddell | Watson Botanical Exchange Club William Robert Sherrin | 31/8/1915 | SLBI |
| Fallopia convolvulus var. subalatum | IE, VCH38 Co. Down, grey abbey | Coslett Herbert Waddell | Watson Botanical Exchange Club William Robert Sherrin | 9/1914 | SLBI |
| Leonurus cardiaca | GB, VC54 North Lincolnshire, Ingoldmells | Helen M Nash | Coslett Herbert Waddell | 11/9/1913 | K |
| Crepis capillaris | IE, VCH19 Co. Kildare, Grey Abbey | Coslett Herbert Waddell | Watson Botanical Exchange Club Coslett Herbert Waddell William Robert Sherrin | 5/7/1913 | SLBI |
+ | Calamagrostis stricta | IE, VCH39 Co. Antrim, Lough Neagh | Coslett Herbert Waddell Nathaniel Carrothers | Watson Botanical Exchange Club Charles Bailey Coslett Herbert Waddell | 29/7/1911 | MANCH |
+ | Viola tricolor | IE, VCH38 Co. Down, Saintfield | Coslett Herbert Waddell | Botanical Exchange Club of The British Isles Charles Bailey Coslett Herbert Waddell | 4/10/1910 | MANCH |
| Viola tricolor subsp. saxatilis | IE, VCH38 Co. Down, Saintfield | Coslett Herbert Waddell | Watson Botanical Exchange Club Augustin Ley Coslett Herbert Waddell | 4/10/1910 | BIRM |
| Rosa sherardii | IE, VCH39 Co. Antrim, Carnlough | Coslett Herbert Waddell | Botanical Exchange Club of The British Isles Coslett Herbert Waddell | 9/8/1910 | BIRM |
| Callitriche hermaphroditica | VCH39, Harbour Island | Coslett Herbert Waddell | Watson Botanical Exchange Club William Robert Sherrin | 18/8/1909 | SLBI |
| Callitriche autumnalis | IE, VCH39 Co. Antrim, Lough Neagh | Coslett Herbert Waddell | Watson Botanical Exchange Club Augustin Ley Coslett Herbert Waddell | 13/8/1909 | BIRM |
| Polygonum aviculare | IE, VCH38 Co. Down, Saintfield | Coslett Herbert Waddell | Watson Botanical Exchange Club Augustin Ley Coslett Herbert Waddell | 8/1909 | BIRM |
| Thymus praecox subsp. arcticus | IE, VCH38 Co. Down, Orlock Point | Coslett Herbert Waddell | Watson Botanical Exchange Club Albert Bruce Jackson Coslett Herbert Waddell | 8/1909 | K |
| Saxifraga umbrosa var. punctata | IE, VCH6 Co. Waterford, Comeragh Mountains Cultivated | Coslett Herbert Waddell | Coslett Herbert Waddell | 7/1909 | BIRM |
| Ranunculus peltatus | IE, VCH38 Co. Down, Saintfield | Coslett Herbert Waddell | Watson Botanical Exchange Club Augustin Ley Coslett Herbert Waddell | 30/6/1909 | BIRM |
| Salix daphnoides | IE, VCH38 Co. Down, Saintfield | Coslett Herbert Waddell | Botanical Exchange Club of The British Isles Augustin Ley Coslett Herbert Waddell | 4/1909 to 8/1909 | BIRM |
| Euphrasia salisburgensis | IE, VCH8 Co. Limerick, Askeaton | Coslett Herbert Waddell | Botanical Exchange Club of The British Isles Augustin Ley Coslett Herbert Waddell | 7/1908 | BIRM |
| Euphrasia salisburgensis | IE, VCH8 Co. Limerick, Ballynort nr. Askeaton | Coslett Herbert Waddell | Watson Botanical Exchange Club Augustin Ley Coslett Herbert Waddell | 7/1908 | BIRM |
| Rumex maritimus | GB, VC37 Worcestershire, Droitwich | Coslett Herbert Waddell | Augustin Ley | 7/8/1907 | BIRM |
| Artemisia vulgaris | GB, VC38 Warwickshire, Newbold on Stour | Coslett Herbert Waddell | Augustin Ley Coslett Herbert Waddell | 25/8/1906 | BIRM |
| Rosa spinosissima x canina = R. x hibernica | IE, VCH38 Co. Down, Holywood | Coslett Herbert Waddell | Allan Octavian Hume | 6/1906 to 7/1906 | SLBI |
+ | Euphrasia nemorosa x brevipila | IE, Nantenan, near Askeaton, co. Limerick. [H8] | Coslett Herbert Waddell | | 11/9/1905 | MANCH |
| Limonium vulgare x humile = L. x neumanii | IE, VCH38 Co. Down, Portaferry | Coslett Herbert Waddell | Allan Octavian Hume Coslett Herbert Waddell | 9/1905 | SLBI |
| Spergularia rupicola | IE, VCH38 Co. Down, Portaferry | Coslett Herbert Waddell | Alfred Loydell William Robert Sherrin | 9/1905 | SLBI |