+ | Thymus diffusus | | | | 9/1834 | MANCH |
+ | Thymus diffusus | | | | | MANCH |
+ | Thymus montanus | | | | | MANCH |
| Thymus serpyllum | | | | | SHYB |
+ | Thymus zygis | | | | | MANCH |
| Thymus serpyllum | IT, Toscana, Lucca | | Allan Octavian Hume Frederick Townsend | | SLBI |
| Thymus praecox subsp. arcticus | IE, VCH40 Co. Londonderry, Mount Benevenagh | Marian Muriel Whiting | | 26/6/1930 | K |
| Thymus praecox subsp. arcticus | IE, VCH40 Co. Londonderry, Magilligan point | John Patrick Micklethwait Brenan Norman Douglas Simpson | | 6/8/1938 | K |
| Thymus praecox subsp. arcticus | IE, VCH40 Co. Londonderry, Castlerock | Marian Muriel Whiting | | 21/6/1930 | K |
| Thymus serpyllum | IE, VCH39 Co. Antrim, Glenariffe | | Shrewsbury Public Library Charles Cardale Babington | 11/9/1852 | K |
| Thymus praecox subsp. arcticus | IE, VCH39 Co. Antrim, Ballycastle | Marian Muriel Whiting | | 20/6/1930 | K |
| 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 |
| Thymus praecox subsp. arcticus | IE, VCH38 Co. Down, Benderg Bay | Robert Desmond Meikle | | 8/1957 | K |
| Thymus praecox subsp. arcticus | IE, VCH33 Fermanagh, Lattone Lough | Edward Norman Carrothers | | 12/7/1948 | K |
| Thymus praecox subsp. arcticus | IE, VCH29 Co. Leitrim, Manorhamilton | Joseph Robert Sealy Stella Ross-Craig | | 7/7/1946 | K |
| Thymus serpyllum | IE, VCH21 Co. Dublin, Portmarnock | Robert Lloyd Praeger | Robert Lloyd Praeger | 30/6/1902 | DBC |
| Thymus praecox subsp. arcticus | IE, VCH16 West Galway, Roundstone | Joseph Robert Sealy Stella Ross-Craig | | 14/7/1946 | K |
| Thymus praecox subsp. arcticus | IE, VCH16 West Galway, Clifden | D Saville | | 28/8/1935 | K |
| Thymus | IE, VCH14 Laois, Maryboro' | Norman Loftus Bor | Norman Loftus Bor | 7/1947 | K |
| Thymus praecox subsp. arcticus | IE, VCH9 Co. Clare, Ballyvaughan | | George Cheetham Churchill | 25/8/1865 | K |
| Thymus praecox subsp. arcticus | IE, VCH9 Co. Clare, Ballyvaughan | Joseph Robert Sealy Stella Ross-Craig | | 22/7/1946 | K |
| Thymus praecox subsp. arcticus | IE, VCH9 Co. Clare, Ballyvaghan | H M Burkill | | 20/8/1958 | K |
| Thymus praecox subsp. arcticus | IE, VCH9 Co. Clare, Ballyvaghan | Joseph Robert Sealy Stella Ross-Craig | | 22/7/1946 | K |
| Thymus praecox subsp. arcticus | IE, VCH3 West Cork, Sherkin Island | Oleg Vladimir Polunin Palmer John Newbould | | 25/7/1949 | K |
| Thymus praecox subsp. arcticus | IE, VCH3 West Cork, Sherkin Island | Oleg Vladimir Polunin Palmer John Newbould | | 23/7/1949 | K |
| Thymus praecox subsp. arcticus | IE, Kerry, Caherbla | Brian Lawrence Burtt Joseph Robert Sealy Stella Ross-Craig | | 8/7/1938 | K |
| Thymus praecox subsp. arcticus | IE, VCH2 North Kerry, Muckross House | Brian Lawrence Burtt Joseph Robert Sealy Stella Ross-Craig | | 29/8/1935 | K |
| Thymus praecox subsp. arcticus | IE, VCH2 North Kerry, Muckross | Brian Lawrence Burtt Joseph Robert Sealy Stella Ross-Craig | | 14/7/1938 | K |
| Thymus praecox subsp. arcticus | IE, VCH2 North Kerry, Muckross | Brian Lawrence Burtt Joseph Robert Sealy Stella Ross-Craig | | 29/8/1935 | K |
| Thymus praecox subsp. arcticus | IE, VCH2 North Kerry, Killarney, Muckross | Brian Lawrence Burtt Joseph Robert Sealy Stella Ross-Craig | | 14/7/1938 | K |
| Thymus praecox subsp. arcticus | IE, VCH1 South Kerry, Ventry Harbour | Brian Lawrence Burtt Joseph Robert Sealy Stella Ross-Craig | | 28/6/1938 | K |
| Thymus praecox subsp. arcticus | IE, VCH1 South Kerry, Ventry Harbour | Brian Lawrence Burtt Joseph Robert Sealy Stella Ross-Craig | | 28/6/1938 | K |
| Thymus serpyllum | IE, VCH1 South Kerry, Valentia Island | Joseph Woods | Allan Octavian Hume Frederick Townsend | 5/7/1855 | SLBI |
| Thymus praecox subsp. arcticus | IE, VCH1 South Kerry, Cummeenduff Glen | Brian Lawrence Burtt Stella Ross-Craig | | 19/6/1938 | K |
| Thymus praecox subsp. arcticus | IE, VCH1 South Kerry, Cummeenduff Glen | Brian Lawrence Burtt Stella Ross-Craig | | 19/6/1938 | K |
| Thymus praecox subsp. arcticus | IE, VCH1 South Kerry, Cummeenduff Glen | Brian Lawrence Burtt Stella Ross-Craig | | 19/6/1938 | K |
| Thymus praecox subsp. arcticus | IE, VCH1 South Kerry, Cummeenduff Glen | Brian Lawrence Burtt Stella Ross-Craig | | 19/6/1938 | K |
| Thymus praecox subsp. arcticus | IE, VCH34,VCH40, Magilligan Point | Norman Douglas Simpson | John Patrick Micklethwait Brenan | 6/8/1938 | K |
| Thymus polytrichus | IE, VCH9,VCH10, Lough Derg | M Hildred Bigwood | | 11/7/1969 | ABS |
| Thymus praecox subsp. arcticus | IE, VCH18,VCH25, Clonmacnoise | David Allardice Webb | Trinity College, Dublin | 30/7/1951 | K |