| Carex paniculata x remota = C. x boenninghauseniana | GB, VC3 South Devon, Caton | Thomas Richard Archer Briggs | Botanical Exchange Club of The British Isles Edward Francis Linton Thomas Richard Archer Briggs | 10/7/1879 | BM |
| Carex paniculata x remota = C. x boenninghauseniana | GB, VC3 South Devon, Ermington | Thomas Richard Archer Briggs | Thomas Richard Archer Briggs | 25/5/1883 | BM |
| Carex paniculata x remota = C. x boenninghauseniana | GB, VC13 West Sussex, Henfield GB, VC3 South Devon, Caton GB, VC32 Northamptonshire | George Chester Thomas Hilton Thomas Richard Archer Briggs | | | MANCH |
| Carex pseudocyperus | GB, VC3 South Devon, Plymbridge | Thomas Richard Archer Briggs | | 13/8/1875 | BM |
| Carex punctata | GB, VC3 South Devon, Bigbury Bay | Thomas Richard Archer Briggs | London Botanical Exchange Club Robert Large Baker | 7/1876 | BIRM |
| Carex rostrata | GB, VC3 South Devon, Dartmoor | Thomas Richard Archer Briggs | Frederick Janson Hanbury John Thomas Irvine Boswell-Syme | 30/6/1868 | BM |
| Carex strigosa | GB, VC58 Cheshire, Cotterill Clough | George Edward Hunt | Botanical Exchange Club of The British Isles Thomas Richard Archer Briggs | 6/1868 | E |
| Carex vulpina | GB, VC2 East Cornwall, Torpoint | Thomas Richard Archer Briggs | | 2/7/1869 | BM |
+ | Cicendia filiformis | GB, VC1 West Cornwall, Porthcurnow | Thomas Richard Archer Briggs | Charles Bailey | 26/7/1866 | MANCH |
+ | Cicendia filiformis | GB, VC4 North Devon | Thomas Richard Archer Briggs | Charles Bailey William Moyle Rogers | 9/1883 | MANCH |
| Clinopodium ascendens | GB, VC3 South Devon, Holbeton | Thomas Richard Archer Briggs | Augustin Ley | 3/8/1874 | BIRM |
+ | Clinopodium ascendens | GB, VC3 South Devon, Ivybridge | Thomas Richard Archer Briggs | Elizabeth Anne Lomax | 15/9/1877 | MANCH |
| Convolvulus arvensis | GB, VC3 South Devon, Down Thomas | Thomas Richard Archer Briggs | Augustin Ley | 26/7/1875 | BIRM |
| Crassula tillaea | GB, VC3 South Devon, Plym Valley | Thomas Richard Archer Briggs | John Ralfs | 23/4/1872 | SLBI |
| Crassula tillaea | GB, VC3 South Devon, Rumple Quarries | Thomas Richard Archer Briggs | London Botanical Exchange Club | 23/4/1872 | BIRM |
| Crepis biennis | GB, VC3 South Devon, Shaugh Bridge | Thomas Richard Archer Briggs | Augustin Ley Thomas Richard Archer Briggs | 9/6/1868 | BIRM |
| Crepis nicaeensis | GB, VC2 East Cornwall, Penters Cross | Thomas Richard Archer Briggs | William Hadden Beeby | 11/6/1878 | SLBI |
| Danaa cornubiensis | GB, VC3 South Devon, Blaxton | Thomas Richard Archer Briggs | Augustin Ley | 7/1868 | BIRM |
| Deschampsia setacea | GB, VC9 Dorset, Canford Heath | Thomas Richard Archer Briggs William Moyle Rogers | Botanical Exchange Club of The British Isles Augustin Ley William Moyle Rogers | 7/1888 | BIRM |
| Drosera intermedia | GB, VC2 East Cornwall, Viverdon Down | Thomas Richard Archer Briggs | London Botanical Exchange Club Robert Large Baker | 8/8/1865 | BIRM |
| Drosera rotundifolia | GB, VC71 Isle of Man, Snaefell | Thomas Richard Archer Briggs | Robert Large Baker | 8/1877 | BIRM |
| Eleocharis parvula | GB, VC3 South Devon, Aveton Gifford | Thomas Richard Archer Briggs | William Hillhouse | 8/1880 | BIRM |
| Elymus pungens | GB, VC2 East Cornwall, Cremyll | Thomas Richard Archer Briggs | | 13/8/1877 | ABS |
+ | Epilobium hirsutum x montanum = E. x erroneum | GB, VC3 South Devon, Eggbuckland | Thomas Richard Archer Briggs | | 2/8/1881 | BIRM |
| Epilobium lanceolatum | GB, VC3 South Devon, Plymouth | Thomas Richard Archer Briggs | | 14/4/1877 | BIRM |
| Erophila verna | GB, VC2 East Cornwall, Torpoint | Thomas Richard Archer Briggs | William Hadden Beeby | 1/4/1874 | SLBI |
| Eryngium campestre | GB, VC3 South Devon, Devil's Point | Thomas Richard Archer Briggs | George Stephen West | 5/10/1876 | BIRM |
+ | Eryngium campestre | GB, VC6 North Somerset, Congresbury | Thomas Richard Archer Briggs | | 1866 | MANCH |
| Galium verum x mollugo = G. x pomeranicum | GB, VC2 East Cornwall, Whitsand Bay | Thomas Richard Archer Briggs | Charles Bailey John Harbord Lewis | 14/7/1869 | MANCH |
| Galium verum x mollugo = G. x pomeranicum | GB, VC3 South Devon, Mothecombe | Thomas Richard Archer Briggs | Charles Bailey | 16/7/1873 | MANCH |
| Galium verum x mollugo = G. x pomeranicum | GB, VC3 South Devon, Wembury | Thomas Richard Archer Briggs | Charles Bailey | 22/7/1875 | MANCH |
| 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 |
| Geranium robertianum | | | William Hadden Beeby Thomas Richard Archer Briggs | 29/5/1888 | SLBI |
| 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 |
| Hypericum undulatum | GB, VC3 South Devon, Plymouth | Thomas Richard Archer Briggs | William Hadden Beeby | 8/1870 | SLBI |
| Hypericum undulatum | GB, VC3 South Devon, Plymouth | Thomas Richard Archer Briggs | Allan Octavian Hume Frederick Townsend | 10/9/1870 | SLBI |
+ | Hypochaeris glabra | GB, VC3 South Devon, Torquay,Dawlish Warren | Thomas Richard Archer Briggs | Charles Bailey | 24/5/1874 | MANCH |
| Illecebrum verticillatum | GB, VC1 West Cornwall, Land's End | Thomas Richard Archer Briggs | Augustin Ley | 26/7/1866 | BIRM |