| Plantago coronopus | GB, VC34 West Gloucestershire, Avonmouth Docks, Bristol | Cecil Ivry Sandwith | | 1/9/1928 | K |
| Plantago coronopus | GB, VC1 West Cornwall, Lizard | Cecil Ivry Sandwith Noel Yvri Sandwith | | 8/6/1937 | K |
| Plantago lanceolata var. anthoviridis | GB, VC6 North Somerset, Tickenham | Cecil Ivry Sandwith Noel Yvri Sandwith | | 15/5/1951 | K |
| Plantago maritima | GB, VC34 West Gloucestershire, Avonmouth Docks, Bristol | Cecil Ivry Sandwith | | 6/1932 | K |
| Polygonum bellardii | GB, VC34 West Gloucestershire, Avonmouth Docks, Bristol | Cecil Ivry Sandwith James Walter White | James Walter White | 27/10/1925 | SLBI |
| Potamogeton gramineus | GB, VC56 Nottinghamshire, Everton Carr | Cecil Ivry Sandwith Noel Yvri Sandwith | Harold Stuart Thompson Arthur Bennett | 30/8/1918 | BIRM |
| Pulsatilla vulgaris | GB, VC33 East Gloucestershire, Snowshill | Cecil Ivry Sandwith Noel Yvri Sandwith | Harold Stuart Thompson | 23/4/1919 | BIRM |
| Rhamnus cathartica | GB, VC34 West Gloucestershire, Clifton Down | Cecil Ivry Sandwith Harold Stuart Thompson | Harold Stuart Thompson | 6/1915 | BIRM |
| Rumex obtusifolius | GB, VC6 North Somerset, Tickenham | Cecil Ivry Sandwith | Job Edward Lousley | 2/10/1940 | SLBI |
| Rumex palustris | GB, VC6 North Somerset, Westhay Moor | Cecil Ivry Sandwith Harold Stuart Thompson | Harold Stuart Thompson | 10/7/1935 | BIRM |
| Scirpus caespitosus | GB, VC6 North Somerset, Black Down | Cecil Ivry Sandwith | Cedric Bucknall Harold Stuart Thompson | 2/6/1915 | BIRM |
| Scrophularia nodosa | GB, VC64 Mid-west Yorkshire, Clapham | Cecil Ivry Sandwith Noel Yvri Sandwith | | 8/7/1934 | K |
| Scrophularia nodosa | GB, VC64 Mid-west Yorkshire, Clapham | Cecil Ivry Sandwith Noel Yvri Sandwith | | 8/7/1934 | K |
| Scrophularia scorodonia | GB, VC41 Glamorganshire, Cardiff, Cardiff Docks | Cecil Ivry Sandwith John Patrick Micklethwait Brenan Royston Leslie Smith | John Patrick Micklethwait Brenan | 4/8/1937 | K |
| Scrophularia umbrosa | GB, VC33 East Gloucestershire, Compton Abdale | Cecil Ivry Sandwith Noel Yvri Sandwith | | 10/9/1936 | K |
| Scrophularia umbrosa | GB, VC33 East Gloucestershire, Compton Abdale | Cecil Ivry Sandwith Noel Yvri Sandwith | | 9/10/1936 | K |
| Scrophularia umbrosa | GB, VC33 East Gloucestershire, Compton Abdale | Cecil Ivry Sandwith Noel Yvri Sandwith | | 10/9/1936 | K |
| Sorbus bristoliensis | GB, VC6 North Somerset, Leigh Woods | Cecil Ivry Sandwith Harold Stuart Thompson | Harold Stuart Thompson | 6/8/1933 | BIRM |
| Sorbus intermedia | GB, VC6 North Somerset, Leigh Woods | Williams Alfred James Wilmott Cecil Ivry Sandwith Harold Stuart Thompson | Harold Stuart Thompson | 16/6/1935 to 5/10/1935 | BIRM |
| Stachys alpina | GB, VC34 West Gloucestershire, Wotton-under-Edge | Cecil Ivry Sandwith | | 8/7/1915 | K |
| Stachys germanica | GB, VC34 West Gloucestershire, Bristol, Baptist Mills | Cecil Ivry Sandwith | | 7/1931 | K |
| Stachys palustris | GB, VC9 Dorset, Portland | Cecil Ivry Sandwith Noel Yvri Sandwith | | 12/7/1928 | K |
| Stachys palustris | GB, VC6 North Somerset, Catcott | Cecil Ivry Sandwith Noel Yvri Sandwith | | 21/7/1958 | K |
| Stachys palustris | GB, VC45 Pembrokeshire, Pembroke | Cecil Ivry Sandwith Noel Yvri Sandwith | | 8/8/1931 | K |
| Teesdalia nudicaulis | GB, VC56 Nottinghamshire, Harworth | Cecil Ivry Sandwith | Harold Stuart Thompson | 6/1915 | BIRM |
| Teucrium chamaedrys | GB, VC11 South Hampshire, Upham | Cecil Ivry Sandwith Noel Yvri Sandwith | | 9/1915 | K |
| Teucrium resupinatum | GB, VC34 West Gloucestershire, Bristol | Cecil Ivry Sandwith Noel Yvri Sandwith | | 25/10/1925 | K |
| Thlaspi perfoliatum | GB, VC33 East Gloucestershire, Snowshill | Cecil Ivry Sandwith Noel Yvri Sandwith | Harold Stuart Thompson | 23/4/1919 | BIRM |
| Verbascum chaixii subsp. chaixii | GB, VC34 West Gloucestershire, Mangotsfield | Cecil Ivry Sandwith Noel Yvri Sandwith | | 10/7/1949 | K |
| Verbascum chaixii subsp. chaixii | GB, VC34 West Gloucestershire, Mangotsfield | Cecil Ivry Sandwith Noel Yvri Sandwith | | 10/7/1949 | K |
| Veronica agrestis | GB, VC45 Pembrokeshire, Saint David's | Cecil Ivry Sandwith Noel Yvri Sandwith | | 17/8/1931 | K |
| Veronica beccabunga | GB, VC6 North Somerset, Weston in Gordano | Cecil Ivry Sandwith Noel Yvri Sandwith | | 9/6/1930 | K |
| Veronica catenata | GB, VC34 West Gloucestershire, Wickwar | Cecil Ivry Sandwith Noel Yvri Sandwith | | 6/9/1936 | K |
| Veronica catenata | GB, VC6 North Somerset, Gurney Slade | Cecil Ivry Sandwith Noel Yvri Sandwith | | 6/8/1959 | K |
| Veronica catenata | GB, VC6 North Somerset, Portbury | Cecil Ivry Sandwith Noel Yvri Sandwith | | 19/6/1929 | K |
| Veronica hederifolia | GB, VC2 East Cornwall, Cornwall,Truro,Tresillian | Cecil Ivry Sandwith | | 27/4/1935 | K |
| Veronica hederifolia | GB, VC26 West Suffolk, Mildenhall | Cecil Ivry Sandwith Edgar Wolston Bertram Handsley Milne-Redhead Herbert Kenneth Airy Shaw M O Shaw Noel Yvri Sandwith | | 6/5/1933 | K |
| Veronica hederifolia subsp. sublobata | GB, VC6 North Somerset, Tickenham | Cecil Ivry Sandwith | | 5/5/1941 | K |
| Veronica longifolia | GB, VC18 South Essex, Dagenham | Cecil Ivry Sandwith Noel Yvri Sandwith | | 27/9/1936 | K |
| Veronica praecox | GB, VC26 West Suffolk, Mildenhall | Cecil Ivry Sandwith Edgar Wolston Bertram Handsley Milne-Redhead Herbert Kenneth Airy Shaw Noel Yvri Sandwith | | 6/5/1933 | K |
| Veronica scutellata | GB, VC6 North Somerset, Nailsea | Cecil Ivry Sandwith Noel Yvri Sandwith | | 1/7/1947 | K |
| Veronica triphyllos | GB, VC26 West Suffolk, Mildenhall | Cecil Ivry Sandwith Edgar Wolston Bertram Handsley Milne-Redhead Herbert Kenneth Airy Shaw Noel Yvri Sandwith | | 6/5/1933 | K |
| Viola | GB, VC6 North Somerset, Leigh Woods | Cecil Ivry Sandwith Harold Stuart Thompson | Harold Stuart Thompson | 12/5/1915 | BIRM |
| Viola lactea | GB, VC41 Glamorganshire, Horton | Cecil Ivry Sandwith Edgar Wolston Bertram Handsley Milne-Redhead Noel Yvri Sandwith Olive Milne-Redhead | | 6/5/1935 | K |
| Viola lactea x riviniana | GB, VC34 West Gloucestershire, Yate Lower Common | Cecil Ivry Sandwith Noel Yvri Sandwith | | 16/5/1948 | K |
| Wolffia arrhiza | GB, VC6 North Somerset, Ashcott, Peat Moor | Cecil Ivry Sandwith | | 19/6/1915 | SLBI |