| Alopecurus bulbosus | GB, VC2 East Cornwall, Calstock | Thomas Richard Archer Briggs | Botanical Exchange Club of The British Isles Robert Large Baker | 31/5/1875 | BIRM |
| Ambrosia artemisiifolia | GB, VC2 East Cornwall, Calstock | Thomas Richard Archer Briggs | Augustin Ley | 12/9/1876 | BIRM |
| Anthoxanthum aristatum subsp. puelii | GB, VC3 South Devon, Newton Ferrers | Thomas Richard Archer Briggs | London Botanical Exchange Club Robert Large Baker | 3/7/1876 | BIRM |
| Anthyllis vulneraria | GB, VC3 South Devon, Bigbury Bay | Thomas Richard Archer Briggs | Frederick Townsend | 5/7/1875 | SLBI |
| Asplenium obovatum | GB, VC3 South Devon, Petertavy | Thomas Richard Archer Briggs | Augustin Ley | 4/8/1866 | BIRM |
| Atriplex laciniata | GB, VC1 West Cornwall, Marazion Green | Thomas Richard Archer Briggs | Augustin Ley Elizabeth Anne Lomax | 8/1875 | BIRM |
| Atriplex patula | GB, VC3 South Devon, Honicknowle | Thomas Richard Archer Briggs | Augustin Ley | 17/7/1875 | BIRM |
| Avena strigosa | GB, VC2 East Cornwall, Looe | Thomas Richard Archer Briggs | | 10/7/1871 | BON |
| Avena strigosa | GB, VC3 South Devon, Tamerton Foliott | Thomas Richard Archer Briggs | Augustin Ley | 6/7/1871 | BIRM |
| Ballota ruderalis | GB, VC33 East Gloucestershire, Gloucester Docks | Gustavus A Ornano St Brody | Thomas Richard Archer Briggs | 1869 | K |
| Barbarea intermedia | GB, VC3 South Devon, Knackers Knowle | Thomas Richard Archer Briggs | Augustin Ley | 15/5/1878 | BIRM |
| Brassica rapa var. briggsii | GB, VC2 East Cornwall, Empacombe | Thomas Richard Archer Briggs | | 29/7/1875 | SLBI |
| Brassica rapa var. briggsii | GB, VC2 East Cornwall, Torpoint | Thomas Richard Archer Briggs | Augustin Ley | 15/6/1872 | BIRM |
| Bromus hordeaceus subsp. thominei | GB, VC2 East Cornwall, Rame Head | Thomas Richard Archer Briggs | Augustin Ley | 14/6/1877 | BIRM |
| Bromus hordeaceus subsp. thominei | GB, VC3 South Devon, Bigbury Bay | Thomas Richard Archer Briggs | Botanical Exchange Club of The British Isles William Hunt Painter | 25/5/1885 | ABS |
| Callitriche hamulata | GB, VC2 East Cornwall, Trematon | Thomas Richard Archer Briggs | Augustin Ley | | BIRM |
| Callitriche hamulata | GB, VC3 South Devon, River Plym | Thomas Richard Archer Briggs | Augustin Ley | 15/6/1880 | BIRM |
| Callitriche obtusangula | GB, VC1 West Cornwall, Scilly Isles,Saint Marys | Frederick Janson Hanbury Thomas Richard Archer Briggs | William Booth Waterfall | 1/7/1877 | K |
| Callitriche obtusangula | GB, VC3 South Devon, Plympton | Thomas Richard Archer Briggs | | 9/1877 | ABS |
| Callitriche obtusangula | GB, VC3 South Devon, Plympton Saint Mary | Thomas Richard Archer Briggs | | 19/9/1888 | K |
| Carduus crispus x nutans = C. x stangii | GB, VC3 South Devon, Elburton | Thomas Richard Archer Briggs | Charles Bailey | 8/7/1871 | MANCH |
| Carduus crispus x nutans = C. x stangii | GB, VC3 South Devon, Elburton | Thomas Richard Archer Briggs | Augustin Ley | 8/7/1871 | BIRM |
| Carduus crispus x nutans = C. x stangii | GB, VC3 South Devon, Leighham | Thomas Richard Archer Briggs | Harold Stuart Thompson | 27/6/1890 | BIRM |
| Carduus pycnocephalus | GB, VC3 South Devon, Plymouth | Thomas Richard Archer Briggs | Botanical Exchange Club of The British Isles | 2/6/1882 | SLBI |
| Carduus pycnocephalus | GB, VC3 South Devon, Plymouth | Thomas Richard Archer Briggs | Botanical Exchange Club of The British Isles Augustin Ley | 22/6/1882 | BIRM |
| Carduus pycnocephalus | GB, VC3 South Devon, Plymouth | Thomas Richard Archer Briggs | Frederick Townsend | 1/7/1878 | SLBI |
| Carex acutiformis | GB, VC3 South Devon, Brixton | Thomas Richard Archer Briggs | Alfred French | 5/1873 | BM |
| Carex arenaria | GB, VC3 South Devon, Mothecombe | Thomas Richard Archer Briggs | | 26/5/1868 | BM |
| Carex divulsa subsp. divulsa | GB, VC3 South Devon, Egg Buckland | Thomas Richard Archer Briggs | Thomas Richard Archer Briggs | 2/6/1868 | BM |
| Carex hirta | GB, VC3 South Devon, Elburton | Thomas Richard Archer Briggs | | 4/7/1874 | BM |
| Carex montana | GB, VC3 South Devon, Bickleigh | Thomas Richard Archer Briggs | | 4/1873 | LAUS |
| Carex montana | GB, VC3 South Devon, Roborough Down | Thomas Richard Archer Briggs | Charles Bailey | 2/6/1873 | MANCH |
| Carex muricata | GB, VC2 East Cornwall, Torpoint | Thomas Richard Archer Briggs | | 15/6/1872 | BM |
| Carex ovalis | GB, VC3 South Devon, Tamerton Foliot | Thomas Richard Archer Briggs | | 14/6/1871 | BM |
| Carex paniculata x remota = C. x boenninghauseniana | GB, VC3 South Devon, Caton | Thomas Richard Archer Briggs | Botanical Exchange Club Charles Bailey | 18/7/1879 | MANCH |
| Carex paniculata x remota = C. x boenninghauseniana | GB, VC3 South Devon, Caton | Thomas Richard Archer Briggs | Botanical Exchange Club of The British Isles John Thomas Irvine Boswell-Syme Thomas Richard Archer Briggs | 7/1879 | BM |
| Carex paniculata x remota = C. x boenninghauseniana | GB, VC3 South Devon, Caton | Thomas Richard Archer Briggs | | 18/7/1879 | BM |
| Carex paniculata x remota = C. x boenninghauseniana | GB, VC3 South Devon, Caton | Thomas Richard Archer Briggs | Botanical Exchange Club of The British Isles Arthur Bennett | 7/1879 | BM |
| Carex paniculata x remota = C. x boenninghauseniana | GB, VC3 South Devon, Caton | Thomas Richard Archer Briggs | Botanical Exchange Club of The British Isles Henry & James Groves | 18/7/1879 | BM |
| Carex paniculata x remota = C. x boenninghauseniana | GB, VC3 South Devon, Caton | Thomas Richard Archer Briggs | Botanical Exchange Club of The British Isles Frederick Janson Hanbury | 7/1879 | BM |