| Galium verum x mollugo = G. x pomeranicum | GB, VC3 South Devon, Wembury | Thomas Richard Archer Briggs | Augustin Ley | 5/8/1875 | BIRM |
| Galium verum x mollugo = G. x pomeranicum | GB, VC3 South Devon, Wembury | Thomas Richard Archer Briggs | Augustin Ley | 22/7/1875 | BIRM |
| Hypericum | GB, VC3 South Devon, Plym Valley | Thomas Richard Archer Briggs | Augustin Ley | 18/7/1868 | BIRM |
| Hypericum undulatum | GB, VC3 South Devon, Plymbridge | Thomas Richard Archer Briggs | Augustin Ley | 6/8/1867 | BIRM |
| Illecebrum verticillatum | GB, VC1 West Cornwall, Land's End | Thomas Richard Archer Briggs | Augustin Ley | 26/7/1866 | BIRM |
| Lolium temulentum | GB, VC3 South Devon, Plympton | Thomas Richard Archer Briggs | Augustin Ley | 3/8/1878 | BIRM |
| Lotus angustissimus | GB, VC2 East Cornwall, Looe | Thomas Richard Archer Briggs | Augustin Ley | 10/7/1871 | BIRM |
+ | Mentha aquatica x spicata = M. x piperita | GB, VC3 South Devon, Plymouth | Thomas Richard Archer Briggs | | 15/9/1876 | BIRM |
| Mentha arvensis x aquatica = M. x verticillata | GB, VC2 East Cornwall, Antony | Thomas Richard Archer Briggs | Augustin Ley | 17/8/1872 | BIRM |
| Mentha arvensis x aquatica = M. x verticillata | GB, VC2 East Cornwall, Carkees | Thomas Richard Archer Briggs | Augustin Ley | 19/8/1873 | BIRM |
| Mentha arvensis x aquatica = M. x verticillata | GB, VC2 East Cornwall, Hatt, Botusfleming | Thomas Richard Archer Briggs | Augustin Ley | 12/9/1876 | BIRM |
| Mentha arvensis x aquatica = M. x verticillata | GB, VC3 South Devon, Egg Buckland | Thomas Richard Archer Briggs | Augustin Ley | 7/9/1877 | BIRM |
| Mentha arvensis x aquatica = M. x verticillata | GB, VC3 South Devon, Plymbridge | Thomas Richard Archer Briggs | Augustin Ley | 23/8/1877 | BIRM |
| Mentha arvensis x aquatica = M. x verticillata | GB, VC3 South Devon, River Tavy | Thomas Richard Archer Briggs | Augustin Ley | 30/8/1875 | BIRM |
| Mentha rubra | GB, VC3 South Devon, Egg Buckland | Thomas Richard Archer Briggs | Augustin Ley | 9/1872 | BIRM |
| Mespilus germanica | GB, VC2 East Cornwall, Saltash | Thomas Richard Archer Briggs | Augustin Ley | 27/5/1871 | BIRM |
| Mespilus germanica | GB, VC3 South Devon, Battisborough | Thomas Richard Archer Briggs | Augustin Ley Thomas Richard Archer Briggs | 26/5/1868 20/8/1868 | BIRM |
| Mespilus germanica | GB, VC39 Staffordshire, Salt | Thomas Richard Archer Briggs | Augustin Ley | 14/5/1888 | BIRM |
| Odontites vernus | GB, VC3 South Devon, Plymouth | Thomas Richard Archer Briggs | Augustin Ley | 19/6/1872 | BIRM |
| Orobanche minor var. maritima | GB, VC2 East Cornwall, Seaton | Thomas Richard Archer Briggs | Augustin Ley | 12/6/1876 | BIRM |
| Orobanche minor var. maritima | GB, VC2 East Cornwall, Whitsand Bay | Thomas Richard Archer Briggs | Augustin Ley | 24/6/1875 | BIRM |
| Polycarpon tetraphyllum | GB, VC3 South Devon, King's Tamerton, Plymouth | Thomas Richard Archer Briggs | George Stephen West | 5/1869 | BIRM |
| Polygonum aviculare | GB, VC3 South Devon, Crabtree | Thomas Richard Archer Briggs | Augustin Ley | 10/9/1877 | BIRM |
| Polygonum rurivagum | GB, VC3 South Devon, Plymouth | Thomas Richard Archer Briggs | Augustin Ley | 25/8/1868 | BIRM |
| Polygonum rurivagum | GB, VC3 South Devon, Plymouth | Thomas Richard Archer Briggs | Augustin Ley | 25/8/1868 | BIRM |
| Prunus spinosa x domestica = P. x fruticans | GB, VC2 East Cornwall, Torpoint | Thomas Richard Archer Briggs | Augustin Ley | 17/4/1876 | BIRM |
| Prunus spinosa x domestica = P. x fruticans | GB, VC2 East Cornwall, Torpoint | Thomas Richard Archer Briggs | Augustin Ley | 19/9/1876 | BIRM |
| Puccinellia fasciculata | GB, VC3 South Devon, Crabtree | Thomas Richard Archer Briggs | Botanical Exchange Club of The British Isles Robert Large Baker | 26/6/1875 | BIRM |
+ | Pyrus cordata | GB, VC2 East Cornwall, Saint John | Thomas Richard Archer Briggs | | 1877 | BIRM |
| Pyrus cordata | GB, VC3 South Devon, Estover | Thomas Richard Archer Briggs | | 9/5/1870 | BIRM |
| Pyrus cordata | GB, VC3 South Devon, Estover | Thomas Richard Archer Briggs | | 4/5/1871 | BIRM |
| Pyrus cordata | GB, VC3 South Devon, Estover | Thomas Richard Archer Briggs | | 21/8/1876 | BIRM |
| Pyrus cordata | GB, VC3 South Devon, Estover | Thomas Richard Archer Briggs | | 11/5/1877 | BIRM |
+ | Pyrus cordata | GB, VC3 South Devon, Estover | Thomas Richard Archer Briggs | | 13/9/1881 | BIRM |
| Ranunculus sardous | GB, VC2 East Cornwall, Sheviock | Thomas Richard Archer Briggs | Augustin Ley | 5/6/1871 | BIRM |
| Reseda alba | GB, VC1 West Cornwall, Saint Marys | Thomas Richard Archer Briggs William Booth Waterfall | Harold Stuart Thompson | 5/1877 | BIRM |
| Rumex | GB, Cornwall | Thomas Richard Archer Briggs | London Botanical Exchange Club Robert Large Baker | | BIRM |
| Rumex conglomeratus x pulcher = R. x muretii | GB, VC3 South Devon, Plymouth | Thomas Richard Archer Briggs | Botanical Exchange Club of The British Isles Augustin Ley | 4/8/1879 | BIRM |
| Rumex conglomeratus x pulcher = R. x muretii | GB, VC85 Fifeshire, Balmuto Cultivated | John Thomas Irvine Syme Thomas Richard Archer Briggs | Botanical Exchange Club of The British Isles Augustin Ley | 9/1879 | BIRM |
| Rumex rupestris | GB, VC2 East Cornwall, Whitsand Bay | Thomas Richard Archer Briggs | Robert Large Baker | 27/7/1877 | BIRM |