+ | Lobelia urens | GB, VC2 East Cornwall, Bodmin (Se of),Lostwithiel | Thomas Richard Archer Briggs | Botanical Exchange Club of The British Isles Charles Bailey | 10/10/1883 | MANCH |
| Lobelia urens | GB, VC2 East Cornwall, Lostwithiel and St.Veep, between | Thomas Richard Archer Briggs | William Hunt Painter | 10/10/1883 | ABS |
| Lobelia urens | GB, VC2 East Cornwall, Saint Lostwithiel | Thomas Richard Archer Briggs | Botanical Exchange Club of The British Isles William Hadden Beeby | 10/10/1883 | SLBI |
| 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, Plym Valley | Thomas Richard Archer Briggs | Charles Cardale Babington | 29/8/1877 | CGE |
+ | Mentha aquatica x spicata = M. x piperita | GB, VC3 South Devon, Plymbridge | Thomas Richard Archer Briggs | Elizabeth Anne Lomax | 23/8/1877 | MANCH |
| Mentha aquatica x spicata = M. x piperita | GB, VC3 South Devon, Plymbridge | Thomas Richard Archer Briggs | Druce Herbarium, Oxford J Fraser | 23/8/1877 | OXF |
+ | Mentha aquatica x spicata = M. x piperita | GB, VC3 South Devon, Plymouth | Thomas Richard Archer Briggs | | 15/9/1876 | BIRM |
| Mentha arvensis | GB, VC2 East Cornwall, Anthony | Thomas Richard Archer Briggs | | 25/8/1876 | K |
| Mentha arvensis | GB, VC2 East Cornwall, Tregantle | Thomas Richard Archer Briggs | | 25/8/1876 | K |
| 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, Carkeel | Thomas Richard Archer Briggs | Charles Cardale Babington | 19/9/1873 | CGE |
| 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, VC2 East Cornwall, Saint Mellion | Thomas Richard Archer Briggs | | 4/9/1877 | CGE |
| Mentha arvensis x aquatica = M. x verticillata | GB, VC3 South Devon, Egg Buckland | Thomas Richard Archer Briggs | Charles Cardale Babington | 7/9/1877 | CGE |
| 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 arvensis x aquatica x spicata = M. x smithiana | GB, VC3 South Devon, Egg Buckland | Thomas Richard Archer Briggs | Charles Cardale Babington | 30/8/1881 | CGE |
| Mentha arvensis x aquatica x spicata = M. x smithiana | GB, VC3 South Devon, Egg Buckland | Thomas Richard Archer Briggs | Charles Cardale Babington | 30/8/1881 | CGE |
| Mentha arvensis x aquatica x spicata = M. x smithiana | GB, VC3 South Devon, Harraton | Thomas Richard Archer Briggs | Allan Octavian Hume Frederick Townsend | 30/7/1878 | SLBI |
| Mentha arvensis x aquatica x spicata = M. x smithiana | GB, VC3 South Devon, Plymstock | Thomas Richard Archer Briggs | | 27/9/1876 | LIV |
| Mentha arvensis x spicata = M. x gracilis | GB, VC2 East Cornwall, Hatt | Thomas Richard Archer Briggs | | 4/9/1877 | CGE |
| Mentha arvensis x spicata = M. x gracilis | GB, VC2 East Cornwall, Hatt, Botus Fleming | Thomas Richard Archer Briggs | | 12/9/1876 | CGE |
| Mentha arvensis x spicata = M. x gracilis | GB, VC2 East Cornwall, Hatt, Botusfleming | Thomas Richard Archer Briggs | | 12/9/1876 | CGE |
| Mentha arvensis x spicata = M. x gracilis | GB, VC3 South Devon, Aveton Gifford | Thomas Richard Archer Briggs | Charles Cardale Babington | 5/8/1880 | CGE |
+ | Mentha arvensis x spicata = M. x gracilis | GB, VC3 South Devon, Common Wood | Thomas Richard Archer Briggs | Charles Bailey | 4/9/1867 | MANCH |
| Mentha arvensis x spicata = M. x gracilis | GB, VC3 South Devon, Diptford | Thomas Richard Archer Briggs | Charles Cardale Babington | 18/8/1881 | CGE |
| Mentha arvensis x spicata = M. x gracilis | GB, VC3 South Devon, Ivybridge | Thomas Richard Archer Briggs | | 15/9/1877 | CGE |
+ | Mentha arvensis x spicata = M. x gracilis | GB, VC3 South Devon, Plym Valley | Thomas Richard Archer Briggs | Charles Bailey | 23/8/1867 | MANCH |
| Mentha pulegium | GB, VC3 South Devon, Holbeton | Thomas Richard Archer Briggs | James Ramsay Drummond | 31/8/1874 | K |
| Mentha rubra | GB, VC3 South Devon, Egg Buckland | Thomas Richard Archer Briggs | Augustin Ley | 9/1872 | BIRM |
| Mentha spicata | GB, VC3 South Devon, Ermington | Thomas Richard Archer Briggs | | 29/8/1876 | K |
| Mentha spicata x suaveolens = M. x villosa var. alopecuroides | GB, Essex GB, VC6 North Somerset, Clifton Cultivated | James Walter White | Albert Bruce Jackson Charles Edgar Salmon David Fry Thomas Richard Archer Briggs | 14/8/1908 | K |
| Mentha x piperita | GB, VC34 West Gloucestershire, Mitcheldean | Augustin Ley | Thomas Richard Archer Briggs | 13/9/1877 | K |
| Mespilus germanica | GB, VC2 East Cornwall, Saltash | Thomas Richard Archer Briggs | William Hadden Beeby | 5/1871 | SLBI |
| 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 |