| Festuca arundinacea | GB, VC6 North Somerset, Clifton Bridge | Cecil Ivry Sandwith Noel Yvri Sandwith | | 9/5/1955 | K |
| Festuca arundinacea | GB, VC11 South Hampshire, Redbridge | Cecil Ivry Sandwith Noel Yvri Sandwith | | 8/7/1928 | K |
| Galeopsis angustifolia | GB, VC12 North Hampshire, East Tisted | Cecil Ivry Sandwith Noel Yvri Sandwith | | 22/8/1915 | K |
| Galeopsis segetum | GB, VC56 Nottinghamshire, Everton Carr | Cecil Ivry Sandwith Noel Yvri Sandwith | | 30/8/1918 | K |
| Galeopsis tetrahit | GB, VC2 East Cornwall, Ruan High Lanes | Cecil Ivry Sandwith Noel Yvri Sandwith | | 14/8/1934 | K |
| Galeopsis versicolor | GB, VC56 Nottinghamshire, Everton Carr | Cecil Ivry Sandwith Noel Yvri Sandwith | | 9/8/1939 | K |
| Groenlandia densa | GB, VC54 North Lincolnshire, Haxey | Cecil Ivry Sandwith Noel Yvri Sandwith | | 8/1939 | K |
| Hypochaeris glabra | GB, VC56 Nottinghamshire, Everton | Cecil Ivry Sandwith Noel Yvri Sandwith | | 9/8/1939 | K |
| Kickxia spuria | GB, VC11 South Hampshire, Hayling Island | Cecil Ivry Sandwith Noel Yvri Sandwith | | 11/9/1927 | K |
| Lamium confertum | GB, VC94 Banffshire, Cullen | Cecil Ivry Sandwith Noel Yvri Sandwith | | 22/7/1938 | K |
| Ligustrum vulgare | GB, VC6 North Somerset, Cleeve Toot | Cecil Ivry Sandwith Noel Yvri Sandwith | | 29/12/1945 | K |
| Limosella australis | GB, VC41 Glamorganshire, Kenfig | Cecil Ivry Sandwith Eleanor Vachell | Eleanor Vachell | 10/1933 | K |
| Linaria repens | GB, VC34 West Gloucestershire, Avonmouth | Cecil Ivry Sandwith Noel Yvri Sandwith | | 21/8/1949 | K |
| Linaria repens | GB, VC34 West Gloucestershire, Chittening Warth | Cecil Ivry Sandwith Noel Yvri Sandwith | | 12/8/1956 | K |
| Linaria vulgaris | GB, VC34 West Gloucestershire, Avonmouth Docks, Bristol Cultivated | Cecil Ivry Sandwith | | 3/10/1940 | K |
| Linaria vulgaris | GB, VC34 West Gloucestershire, Avonmouth Docks, Bristol | Cecil Ivry Sandwith Noel Yvri Sandwith | | 9/1935 | K |
| Linaria vulgaris | GB, VC34 West Gloucestershire, Avonmouth Docks, Bristol | Cecil Ivry Sandwith Noel Yvri Sandwith | | 9/1935 | K |
| Linaria vulgaris x repens = L. x sepium | GB, VC14 East Sussex, Lewes | Cecil Ivry Sandwith Noel Yvri Sandwith | | 24/8/1930 | K |
| Linaria vulgaris x repens = L. x sepium | GB, VC34 West Gloucestershire, Avonmouth | Cecil Ivry Sandwith Noel Yvri Sandwith | | 12/8/1956 | K |
| Melissa officinalis | GB, VC41 Glamorganshire, Roath | Cecil Ivry Sandwith John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 6/8/1937 | K |
| Mentha aquatica | GB, VC9 Dorset, Stoborough | Cecil Ivry Sandwith | | 25/8/1933 | K |
| Mentha aquatica | GB, VC41 Glamorganshire, Kenfig Pool | Cecil Ivry Sandwith | | 20/9/1933 | K |
| Mentha aquatica x spicata = M. x piperita | GB, VC46 Cardiganshire, Mount | Cecil Ivry Sandwith Noel Yvri Sandwith | | 9/1932 | K |
| Mentha arvensis | GB, VC6 North Somerset, Cranmore | Cecil Ivry Sandwith Noel Yvri Sandwith | | 30/7/1941 | K |
| Mentha arvensis | GB, VC10 Isle of Wight, Apesdown | Cecil Ivry Sandwith | | 8/1933 | K |
| Mentha arvensis var. densifoliata | GB, VC34 West Gloucestershire, Yate | Cecil Ivry Sandwith | J Fraser | 1/10/1932 | K |
| Mentha arvensis x aquatica = M. x verticillata | GB, VC28 West Norfolk, Ring Mere | Cecil Ivry Sandwith Noel Yvri Sandwith | Noel Yvri Sandwith | 21/8/1926 | K |
| Mentha arvensis x aquatica x spicata = M. x smithiana | GB, VC34 West Gloucestershire, Golden Valley | Cecil Ivry Sandwith Noel Yvri Sandwith | | 11/9/1933 | K |
| Mentha arvensis x aquatica x spicata = M. x smithiana | GB, VC46 Cardiganshire, Mount | Cecil Ivry Sandwith Noel Yvri Sandwith | | 9/9/1932 | K |
| Mentha arvensis x spicata = M. x gracilis | GB, VC6,VC34, Bedminster | Cecil Ivry Sandwith Noel Yvri Sandwith | Noel Yvri Sandwith | 8/9/1930 | K |
| Mentha gentilis var. gracilis | GB, VC6 North Somerset, Sharpham Moor | Cecil Ivry Sandwith Noel Yvri Sandwith | | 13/9/1933 | K |
| Mentha piperita var. piperita | GB, VC6 North Somerset, Charterhouse on Mendip | Cecil Ivry Sandwith Noel Yvri Sandwith | | 8/8/1959 | K |
| Mentha piperita var. piperita | GB, VC6 North Somerset, Charterhouse on Mendip | Cecil Ivry Sandwith Noel Yvri Sandwith | | 8/8/1959 | K |
| Mentha piperita var. piperita | GB, VC8 South Wiltshire, Semley | Cecil Ivry Sandwith Noel Yvri Sandwith | | 14/9/1955 | K |
| Mentha spicata | GB, VC2 East Cornwall, Veryan | Cecil Ivry Sandwith Noel Yvri Sandwith | | 14/8/1934 | K |
| Mentha spicata x suaveolens = M. x villosa var. alopecuroides | GB, VC28 West Norfolk, Thetford | Cecil Ivry Sandwith | | 22/8/1926 | K |
| Mentha spicata x suaveolens = M. x villosa var. alopecuroides | GB, VC28 West Norfolk, Thetford | Cecil Ivry Sandwith | | 22/8/1926 | K |
| Mentha suaveolens | GB, VC35 Monmouthshire, Mitchel Troy | Cecil Ivry Sandwith | | 23/9/1933 | K |
| Mentha suaveolens | GB, VC41 Glamorganshire, Cardiff, Cardiff Docks | Cecil Ivry Sandwith John Patrick Micklethwait Brenan | | 11/9/1935 | K |
| Mentha suaveolens | GB, VC41 Glamorganshire, Cardiff, Cardiff Docks | Cecil Ivry Sandwith Noel Yvri Sandwith | | 11/9/1936 | K |