| Acer campestre | GB, VC16 West Kent, Eltham | | | 6/1888 | ABS |
| Acer campestre | GB, VC19 North Essex, Easton | | | 5/1864 | ABS |
| Acer campestre | GB, Essex, Wood Green | | | 8/1869 | ABS |
| Acer pseudoplatanus | GB, VC19 North Essex, Easton | | | 10/5/1864 | ABS |
| Aceras anthropophorum | GB, VC15 East Kent, Detling | | | | ABS |
| Achillea millefolium | GB, VC64 Mid-west Yorkshire, Stainforth | | | 8/1963 | ABS |
| Achillea millefolium | GB, VC57 Derbyshire, Beeley | | | 19/9/1965 | ABS |
| Achillea millefolium | GB, VC51 Flintshire, Dyserth | | | | ABS |
| Achillea ptarmica | GB, VC63 South-west Yorkshire, Barnby Dun | | | 8/1874 | ABS |
| Aconitum napellus | GB, VC69 Westmorland, Windermere,Waterhead | | | 22/8/1863 | ABS |
| Adonis autumnalis | GB, VC9 Dorset, Portland | | | 26/7/1865 | ABS |
| Adoxa moschatellina | GB, VC63 South-west Yorkshire, Hooton Roberts | | | 3/1874 | ABS |
| Aegopodium podagraria | GB, VC21 Middlesex, Islington Cultivated | | | 29/6/1902 | ABS |
| Aesculus hippocastanum | GB, VC13 West Sussex, Findon | | | 5/1886 | ABS |
| Aethusa cynapium | GB, VC16 West Kent, Charlton | | | 10/1879 | ABS |
| Aethusa cynapium | GB, VC20 Hertfordshire, Barnet | | | 4/9/1967 | ABS |
| Aethusa cynapium | GB, VC9 Dorset, Weymouth | | | 7/1865 | ABS |
| Agrimonia eupatoria | GB, VC63 South-west Yorkshire, Conisborough | | | 7/1875 | ABS |
| Agrimonia eupatoria | GB, VC51 Flintshire, Dyserth | | | 8/8/1960 | ABS |
| Agrostis capillaris | GB, VC87 West Perthshire, Ben Lui | | | 9/8/1879 | ABS |
| Agrostis curtisii | GB, VC3 South Devon, Newton Abbot | | | 15/8/1882 | ABS |
| Agrostis curtisii | GB, VC1 West Cornwall, Helston | | | 8/7/1879 | ABS |
| Agrostis gigantea | GB, VC37 Worcestershire, Churchill | | | 31/7/1882 | ABS |
| Agrostis stolonifera | GB, VC29 Cambridgeshire, Madingley | | | 11/7/1934 | ABS |
| Agrostis stolonifera | GB, VC49 Caernarvonshire, Llandudno | | | | ABS |
| Agrostis stolonifera | GB, VC6 North Somerset, Weston-super-Mare | | | 25/7/1882 | ABS |
| Agrostis stolonifera | GB, VC1 West Cornwall, Loe Pool | | | 10/7/1879 | ABS |
| Agrostis stolonifera x Polypogon monspeliensis = x Agropogon littoralis | GB, VC18 South Essex, Canvey Island | | | 1879 | ABS |
| Aira caryophyllea | GB, VC46 Cardiganshire, Aberystwyth | | | 5/1922 | ABS |
| Aira caryophyllea | GB, VC41 Glamorganshire, Rhossili Down | | | 29/6/1937 | ABS |
| Aira praecox | GB, VC46 Cardiganshire, Aberystwyth | | | 1920 | ABS |
| Aira praecox | GB, VC37 Worcestershire, Habberley valley | | | 6/1885 | ABS |
| Ajuga reptans | GB, VC14 East Sussex, Saint Leonards | | | 4/1862 | ABS |
| Alchemilla alpina | GB, VC97 West Inverness-shire, Ben Nevis | | | 8/8/1938 | ABS |
| Alchemilla alpina | GB, VC88 Mid Perthshire, Ben Lawers | | | 20/9/1983 | ABS |
| Alchemilla alpina | GB, VC70 Cumberland, Borrowdale | | | 1/7/1890 | ABS |
| Alchemilla filicaulis | GB, VC40 Shropshire, Church Stretton | | | 22/5/1904 | ABS |
| Alchemilla vulgaris | GB, VC41 Glamorganshire, Morlais Glen | | | | ABS |
| Alchemilla vulgaris | GB, VC63 South-west Yorkshire, Conisborough | | | 5/1875 | ABS |
| Alisma plantago-aquatica | GB, VC63 South-west Yorkshire, Doncaster | | | 8/1875 | ABS |