| Melittis melissophyllum | GB, VC3 South Devon, Newton Abbot | Wilson Crosfield Worsdell | George Valentine Chapman Last | 5/1925 | K |
| Mentha aquatica | GB, VC49 Caernarvonshire, Llandudno | George Valentine Chapman Last | George Valentine Chapman Last | 23/9/1906 | K |
| Mentha aquatica | GB, VC59 South Lancashire, Hightown | George Valentine Chapman Last | George Valentine Chapman Last | 26/8/1894 | K |
| Mentha aquatica | IE, VCH38 Co. Down, Warrenpoint | George Valentine Chapman Last | George Valentine Chapman Last | 19/8/1895 | K |
| Mentha aquatica x spicata = M. x piperita | GB, VC98 Argyllshire, Kilchrenan | George Valentine Chapman Last | George Valentine Chapman Last | 4/9/1919 | K |
| Mentha arvensis var. obtusifolia | GB, VC3 South Devon, Bovey Tracey | Wilson Crosfield Worsdell | George Valentine Chapman Last | 7/1924 | K |
| Mentha arvensis | GB, VC113 Channel Islands, Jersey | George Valentine Chapman Last | George Valentine Chapman Last | 3/8/1897 | K |
| Mentha arvensis x aquatica = M. x verticillata | GB, VC3 South Devon, Bovey Tracey | Wilson Crosfield Worsdell | George Valentine Chapman Last | 8/1924 | K |
| Mentha gentilis var. varigata | GB, VC69 Westmorland, Arnside | Wilson Crosfield Worsdell | George Valentine Chapman Last | 9/1906 | K |
| Mentha pulegium | Cultivated | George Valentine Chapman Last | George Valentine Chapman Last | 31/8/1904 | K |
| Mentha pulegium | GB, VC3 South Devon, Torcross | Wilson Crosfield Worsdell | George Valentine Chapman Last | 15/9/1923 | K |
| Mentha spicata x longifolia = M. x villosonervata | GB, VC51 Flintshire, Saint Asaph | George Valentine Chapman Last | George Valentine Chapman Last | 24/8/1922 | K |
| Mentha spicata x longifolia = M. x villosonervata | GB, VC59 South Lancashire, Freshfield Cultivated | George Valentine Chapman Last | George Valentine Chapman Last | 8/1941 | K |
| Mentha spicata x suaveolens = M. x villosa var. alopecuroides | Cultivated | George Valentine Chapman Last | George Valentine Chapman Last | 1/9/1942 | K |
| Mentha spicata x suaveolens = M. x villosa | GB, VC1 West Cornwall, Newquay | Wilson Crosfield Worsdell | George Valentine Chapman Last | 8/1922 | K |
| Mentha spicata x suaveolens = M. x villosa | GB, VC15 East Kent, Wye | C Johnson | George Valentine Chapman Last | 18/8/1937 | K |
| Mentha suaveolens | GB, VC3 South Devon, Scabbacombe | Wilson Crosfield Worsdell | George Valentine Chapman Last | 5/9/1942 | K |
| Mentha suaveolens | IE, VCH38 Co. Down, Warrenpoint | George Valentine Chapman Last | George Valentine Chapman Last | 24/7/1895 | K |
| Mentha x muelleriana | GB, VC3 South Devon, Salcombe | Stephenson | George Valentine Chapman Last | 1924 | K |
| Meum athamanticum | GB, VC50 Denbighshire, Pentrefoelas | A Wilson | George Valentine Chapman Last | 15/8/1935 | K |
| Meum athamanticum | GB, VC69 Westmorland, Dillicar Common | George Valentine Chapman Last | George Valentine Chapman Last | 8/6/1941 | K |
| Meum athamanticum | GB, VC90 Angus, Clova | Wilson Crosfield Worsdell | George Valentine Chapman Last | 12/7/1894 | K |
| Meum athamanticum | GB, VC90 Angus, Clova | Wilson Crosfield Worsdell | George Valentine Chapman Last | 12/7/1894 | K |
| Misopates orontium | GB, VC9 Dorset, Studland | Wilson Crosfield Worsdell | George Valentine Chapman Last | 7/1937 | K |
| Misopates orontium | GB, VC45 Pembrokeshire, Broad Haven | George Valentine Chapman Last | George Valentine Chapman Last | 3/7/1939 | K |
| Misopates orontium | GB, VC45 Pembrokeshire, Fishguard | George Valentine Chapman Last | George Valentine Chapman Last | 1/7/1939 | K |
| Monotropa hypopitys | GB, VC17 Surrey, Shere | Wilson Crosfield Worsdell | George Valentine Chapman Last | 2/8/1936 | K |
| Monotropa hypopitys | GB, VC59 South Lancashire, Freshfield | George Valentine Chapman Last | | 13/8/1942 | K |
| Monotropa hypopitys | GB, VC69 Westmorland, Arnside | Crosland | George Valentine Chapman Last | 14/8/1896 | K |
| Narcissus tazetta x poeticus = N. x medioluteus | GB, VC58 Cheshire, Wirral Peninsula | George Valentine Chapman Last | Arthur John Farmer | 24/4/1942 | MANCH |
| Oenanthe fistulosa | GB, VC7 North Wiltshire, Limpley Stoke | George Valentine Chapman Last | George Valentine Chapman Last | 6/1905 | K |
| Oenanthe fistulosa | GB, VC58 Cheshire, Meols | George Valentine Chapman Last | George Valentine Chapman Last | 10/9/1894 | K |
| Ophrys insectifera | GB, VC22 Berkshire, Newbury | Arthur Reginald Horwood | George Valentine Chapman Last | 8/6/1903 | K |
| Ophrys insectifera | GB, VC56 Nottinghamshire, Worksop | Hubert Frederick Dovaston | George Valentine Chapman Last | 18/5/1943 | K |
| Orchis morio | GB, VC58 Cheshire, Seacombe | George Valentine Chapman Last | George Valentine Chapman Last | 3/6/1904 | K |
| Orchis ustulata | GB, VC8 South Wiltshire, Salisbury Plain | Frederick Kirkwood Makins | George Valentine Chapman Last | 30/5/1940 | K |
| Orchis ustulata | GB, VC69 Westmorland, Arnside | Wilson Crosfield Worsdell | George Valentine Chapman Last | 6/1894 | K |
| Origanum vulgare | GB, VC9 Dorset, Corfe Castle | Wilson Crosfield Worsdell | George Valentine Chapman Last | 7/1935 | K |
| Origanum vulgare | GB, VC49 Caernarvonshire, Great Orme | George Valentine Chapman Last | George Valentine Chapman Last | 22/7/1894 | K |
| Origanum vulgare | GB, VC69 Westmorland, Arnside | Wilson Crosfield Worsdell | George Valentine Chapman Last | 7/1895 | K |