| Mentha aquatica x spicata = M. x piperita | GB, VC41 Glamorganshire, Dinas Powis GB, VC41 Glamorganshire, Wenvoe | S Dewar | Botanical Exchange Club of The British Isles Druce Herbarium, Oxford National Museum of Wales Arthur Edward Wade | 14/9/1932 | OXF |
| Mentha aquatica x spicata = M. x piperita | GB, VC41 Glamorganshire, Dinas Powis | S Dewar | Botanical Exchange Club of The British Isles National Museum of Wales Job Edward Lousley | 14/9/1932 | SLBI |
| Mentha aquatica x spicata = M. x piperita | GB, VC41 Glamorganshire, Dinas Powis | S Dewar | Botanical Exchange Club of The British Isles National Museum of Wales | 14/9/1932 | SLBI |
| Mentha aquatica x spicata = M. x piperita | GB, VC48 Merionethshire, Llanycil | J A Webb | National Museum of Wales Job Edward Lousley | 26/9/1941 | K |
| Mentha arvensis | GB, VC35,VC36, Skenfrith | Samuel George Charles | National Museum of Wales | 9/1934 | K |
| Mentha arvensis x aquatica = M. x verticillata | GB, VC35 Monmouthshire, Redbrook | Samuel George Charles | National Museum of Wales | 8/1924 | K |
| Mentha arvensis x aquatica = M. x verticillata | GB, VC35,VC41, llanedeyrn, Cardiff | Arthur Edward Wade | National Museum of Wales Job Edward Lousley | 5/8/1941 | K |
| Mentha arvensis x aquatica = M. x verticillata | GB, VC47 Montgomeryshire, Llanfair Caereinion | J A Webb | National Museum of Wales Job Edward Lousley | 15/8/1940 | K |
| Mentha arvensis x aquatica = M. x verticillata | GB, VC48 Merionethshire, Bala Lake | J A Webb | National Museum of Wales Job Edward Lousley | 26/9/1941 | K |
| Mentha arvensis x aquatica x spicata = M. x smithiana | GB, VC35 Monmouthshire, Kymin Hill | Samuel George Charles | National Museum of Wales | 9/1934 | K |
| Mentha piperita var. piperita | GB, VC41 Glamorganshire, Dinas Powis | S Dewar | National Museum of Wales J Fraser | 14/9/1932 | K |
| Mentha spicata | GB, VC59 South Lancashire, Bootle | James Alfred Wheldon | National Museum of Wales Watson Botanical Exchange Club Job Edward Lousley | 21/8/1924 | SLBI |
| Mentha spicata | GB, VC59 South Lancashire, Bootle | James Alfred Wheldon | Watson Botanical Exchange Club National Museum of Wales | 21/8/1924 | SLBI |
| Mentha spicata | GB, VC59 South Lancashire, Bootle | James Alfred Wheldon | National Museum of Wales Watson Botanical Exchange Club Isaac A Helsby | 21/8/1924 | SLBI |
| Mentha spicata | GB, VC59 South Lancashire, Bootle | James Alfred Wheldon | National Museum of Wales Arthur Bennett Harold Stuart Thompson J Fraser | 21/8/1924 | BIRM |
| Mentha spicata x suaveolens = M. x villosa var. alopecuroides | GB, VC41 Glamorganshire, Cardiff | Arthur Edward Wade | Botanical Society & Exchange Club of The British Isles National Museum of Wales | 26/8/1947 | K |
| Mentha spicata x suaveolens = M. x villosa | GB, VC41 Glamorganshire, Cardiff | Arthur Edward Wade | Botanical Society & Exchange Club of The British Isles National Museum of Wales | 26/8/1947 | SLBI |
| Mentha spicata x suaveolens = M. x villosa | GB, VC41 Glamorganshire, Peterston-super-Ely | Arthur Edward Wade Charles Edward Britton | Botanical Exchange Club of The British Isles National Museum of Wales | 7/1921 | K |
| Mentha suaveolens | GB, VC35 Monmouthshire, Dixton | Samuel George Charles | National Museum of Wales | 9/1934 | K |
| Mentha x piperita var. subcordata | GB, VC41 Glamorganshire, Dinas Powis | S Dewar | Botanical Exchange Club of The British Isles National Museum of Wales | 14/9/1932 | K |
| Myosotis laxa subsp. caespitosa | GB, VC41 Glamorganshire, Cardiff, Llanedeyrn | Arthur Edward Wade | Botanical Exchange Club of The British Isles National Museum of Wales Job Edward Lousley | 10/7/1930 | SLBI |
| Myosotis laxa subsp. caespitosa | GB, VC35,VC41, llanedeyrn, Cardiff | Arthur Edward Wade | Botanical Society & Exchange Club of The British Isles National Museum of Wales | 10/7/1930 | SLBI |
| Narcissus pseudonarcissus | GB, VC45 Pembrokeshire, Tenby | W Gunter | Watson Botanical Exchange Club Harold Stuart Thompson National Museum of Wales | 1917 | BIRM |
| Neslia paniculata | GB, VC41 Glamorganshire, Splott | Arthur Edward Wade | Watson Botanical Exchange Club National Museum of Wales | 9/1925 | SLBI |
| Parnassia palustris | GB, VC59 South Lancashire, Birkdale | James Alfred Wheldon | National Museum of Wales Watson Botanical Exchange Club | 23/8/1924 | BIRM |
| Parnassia palustris | GB, VC59 South Lancashire, Birkdale | James Alfred Wheldon | National Museum of Wales Watson Botanical Exchange Club James Alfred Wheldon | 23/8/1924 | SLBI |
| Parnassia palustris | GB, VC59 South Lancashire, Birkdale | James Alfred Wheldon | Watson Botanical Exchange Club Job Edward Lousley National Museum of Wales | 23/8/1924 | SLBI |
| Persicaria lapathifolia | GB, VC35 Monmouthshire, Rhymney | Arthur Edward Wade | Botanical Society & Exchange Club of The British Isles National Museum of Wales Harold Stuart Thompson | 3/10/1934 | BIRM |
| Petrorhagia prolifera | GB, VC45 Pembrokeshire, Tenby | Joseph Edmund Arnett | National Museum of Wales Watson Botanical Exchange Club | 14/8/1926 | SLBI |
| Phalaris arundinacea | GB, VC41 Glamorganshire, Cardiff | Ruth Davies | Botanical Society of The British Isles National Museum of Wales | 6/1951 | K |
| Plantago lanceolata | GB, VC43 Radnorshire, Radnor Forest | Harold Augustus Hyde | National Museum of Wales | 1/6/1927 | K |
| Plantago media var. monnieri | GB, VC41 Glamorganshire, Penarth | Arthur Edward Wade | National Museum of Wales | 6/1949 | K |
| Poa balfourii | GB, VC98 Argyllshire, Beinn a' Chreachain | William Andrew Shoolbred | Watson Botanical Exchange Club Harold Stuart Thompson William Andrew Shoolbred National Museum of Wales | 2/8/1898 | BIRM |
| Poa balfourii | GB, VC98 Argyllshire, Beinn an Dothaidh | William Andrew Shoolbred | National Museum of Wales Harold Stuart Thompson | 26/5/1893 | BIRM |
| Poa bulbosa | GB, VC41 Glamorganshire, Barry | Arthur Edward Wade | Watson Botanical Exchange Club Harold Stuart Thompson National Museum of Wales | 5/1920 | BIRM |
| Potamogeton gramineus | GB, VC59 South Lancashire, Ainsdale | James Alfred Wheldon | Botanical Exchange Club of The British Isles National Museum of Wales | 14/7/1924 | E |
| Potamogeton gramineus | GB, VC59 South Lancashire, Ainsdale | James Alfred Wheldon | Botanical Exchange Club of The British Isles National Museum of Wales | 14/7/1924 | SLBI |
| Poterium sanguisorba subsp. balearicum | GB, VC55 Leicestershire, Dunckley Hill, Rutland | Arthur Reginald Horwood | National Museum of Wales | 8/1916 | SLBI |
| Primula elatior | GB, Stony Stratford | James Henry Augustus Steuart | Watson Botanical Exchange Club National Museum of Wales | 3/1889 | SLBI |
| Pyrola rotundifolia subsp. maritima | GB, VC59 South Lancashire, Ainsdale Dunes | J Davy Dean | Watson Botanical Exchange Club National Museum of Wales | 1928 | SLBI |