| Lactuca serriola | IT, Eisack Thal | Augustin Ley | Augustin Ley | 11/8/1865 | BIRM |
| Eriophorum vaginatum | IT | | Botanical Exchange Club of The British Isles Augustin Ley George Claridge Druce | 7/1886 | BIRM |
| Oxalis corniculata | IT | Augustin Ley | Augustin Ley | 6/7/1875 | BIRM |
| Myosotis arvensis | IS, Reykjavik | Francis Augustus Walker | Augustin Ley | 13/6/1890 to 15/6/1890 | BIRM |
| Rumex acetosa | IS, Reykjavik | Francis Augustus Walker | Augustin Ley | 6/1890 | BIRM |
| Ulmus diversifolia | IE, Ambiguous locality (IE), Lismore Castle | Harry Corbyn Levinge | Augustin Ley | 8/1878 | BIRM |
| Senecio vulgaris var. radiatus | IE, Ambiguous locality (IE), Killarney | George Claridge Druce | Botanical Exchange Club of The British Isles Augustin Ley George Claridge Druce | 6/1890 | BIRM |
| Polygala vulgaris | IE, Ambiguous locality (IE), Glencar | | Augustin Ley Edward Francis Linton | 13/8/1891 | BIRM |
| Barbarea intermedia | IE, VCH39 Co. Antrim, Whitewell, Belfast | Samuel Alexander Stewart | Botanical Exchange Club of The British Isles Augustin Ley | 15/6/1879 | BIRM |
| Potamogeton perfoliatus x crispus = P. x cooperi | IE, VCH39 Co. Antrim, Templepatrick | Samuel Alexander Stewart | Botanical Exchange Club of The British Isles Augustin Ley | 10/8/1894 | BIRM |
| Viola tricolor subsp. curtisii | IE, VCH39 Co. Antrim, Portrush | Charles Bailey | Botanical Exchange Club of The British Isles Augustin Ley | 15/7/1896 | BIRM |
| Bidens cernua | IE, VCH39 Co. Antrim, Portmore Lough | Samuel Alexander Stewart | Botanical Exchange Club of The British Isles Augustin Ley | 27/8/1886 | BIRM |
| Carex elata | IE, VCH39 Co. Antrim, Portmore | Samuel Alexander Stewart | Augustin Ley | 20/6/1872 | BIRM |
| Callitriche autumnalis | IE, VCH39 Co. Antrim, Lough Neagh | Coslett Herbert Waddell | Watson Botanical Exchange Club Augustin Ley Coslett Herbert Waddell | 13/8/1909 | BIRM |
| Viola tricolor subsp. curtisii | IE, VCH39 Co. Antrim, Lough Neagh | Samuel Alexander Stewart | Botanical Exchange Club of The British Isles Augustin Ley | 25/6/1886 | BIRM |
| Elatine hexandra | IE, VCH39 Co. Antrim, Lagan Canal | William Mateer | Augustin Ley | 8/1847 | BIRM |
| Euphrasia curta var. glabrescens | IE, VCH39 Co. Antrim, Giants Causeway | Frederick Arundel Rogers | Augustin Ley | 7/1901 | BIRM |
| Equisetum hyemale x variegatum = E. x trachyodon | IE, VCH39 Co. Antrim, Colin Glen | Samuel Alexander Stewart | Augustin Ley | 1/7/1872 | BIRM |
| Equisetum hyemale x variegatum = E. x trachyodon | IE, VCH39 Co. Antrim, Colin Glen | Samuel Alexander Stewart | Botanical Exchange Club of The British Isles Augustin Ley | 29/7/1893 | BIRM |
| Orobanche alba | IE, VCH39 Co. Antrim, Cave Hill, Belfast | Samuel Alexander Stewart | Augustin Ley | 8/7/1871 | BIRM |
| Linaria repens | IE, VCH38 Co. Down, Spelgo Mountain | Frederick Janson Hanbury | Augustin Ley | 7/1891 | BIRM |
| Mentha spicata | IE, VCH38 Co. Down, Saintfield Cultivated | Coslett Herbert Waddell | Watson Botanical Exchange Club Augustin Ley Coslett Herbert Waddell | 7/1902 | BIRM |
| Polygonum aviculare | IE, VCH38 Co. Down, Saintfield | Coslett Herbert Waddell | Watson Botanical Exchange Club Augustin Ley Coslett Herbert Waddell | 8/1909 | 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 |
| 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 |
| Camelina alyssum | IE, VCH38 Co. Down, Newtownards | Edward Francis Linton | Augustin Ley | 7/1871 | BIRM |
| Camelina sativa | IE, VCH38 Co. Down, Newtownards | William Richardson Linton | Augustin Ley | 7/1871 | BIRM |
| Lolium remotum | IE, VCH38 Co. Down, Newtownards | Edward Francis Linton | Augustin Ley | 7/1871 | BIRM |
| Puccinellia maritima | IE, VCH38 Co. Down, Killyleagh | George Claridge Druce | Botanical Exchange Club of The British Isles Augustin Ley George Claridge Druce | 8/1909 | BIRM |
| Atriplex laciniata | IE, VCH38 Co. Down, Groomport | Samuel Alexander Stewart | Augustin Ley | 10/9/1870 | BIRM |
| Viola tricolor subsp. curtisii | IE, VCH38 Co. Down, Dundrum | Coslett Herbert Waddell | Watson Botanical Exchange Club Augustin Ley Coslett Herbert Waddell | 26/4/1902 | BIRM |
| Valerianella carinata | IE, VCH38 Co. Down, Dundonald | Samuel Alexander Stewart | Augustin Ley | 19/6/1877 | BIRM |
| Apium nodiflorum x inundatum = A. x moorei | IE, VCH38 Co. Down, Downpatrick,Quoile | Samuel Alexander Stewart | Botanical Exchange Club of The British Isles Augustin Ley | 7/1880 | BIRM |
| Carex arenaria | IE, VCH38 Co. Down, Co. Down | Samuel Alexander Stewart | Botanical Exchange Club of The British Isles Augustin Ley | 6/1876 | BIRM |
| Ranunculus baudotii | IE, VCH38 Co. Down, Belfast, Harbour | Coslett Herbert Waddell | Augustin Ley Coslett Herbert Waddell | 10/7/1902 | BIRM |
| Melampyrum pratense | IE, VCH36 Tyrone, Clogher Valley | Charlotte L Peck | Botanical Exchange Club of The British Isles Augustin Ley | 6/1907 | BIRM |
| Veronica peregrina | IE, VCH36 Tyrone, Clogher Valley | Charlotte L Peck | Botanical Exchange Club of The British Isles Augustin Ley | 6/1907 | BIRM |
| Viola riviniana | IE, VCH36 Tyrone, Clogher | Charlotte L Peck | Botanical Exchange Club of The British Isles Augustin Ley Eliza Standerwick Gregory | 5/1905 | BIRM |
| Viola riviniana var. minor | IE, VCH36 Tyrone, Clogher | Charlotte L Peck | Botanical Exchange Club of The British Isles Augustin Ley Eliza Standerwick Gregory | 4/1907 | BIRM |