| Bromus hordeaceus | GB, VC1 West Cornwall, Lizard Cultivated | John Thomas Irvine Boswell-Syme | | | ABS |
| Bromus hordeaceus subsp. hordeaceus | GB, VC1 West Cornwall, Lizard Cultivated | John Thomas Irvine Boswell-Syme | | 6/1874 | BON |
| Carex arenaria | GB, VC1 West Cornwall, Scilly Isles,Saint Marys | James Cunnack | Frederick Janson Hanbury John Thomas Irvine Boswell-Syme | 15/6/1883 | BM |
| Daucus maritimus | GB, VC1 West Cornwall, Whitesand Bay | John Thomas Irvine Boswell-Syme | Augustin Ley | 1866 | BIRM |
| Rumex conglomeratus x pulcher = R. x muretii | GB, VC2 East Cornwall, Torpoint Cultivated | John Thomas Irvine Boswell-Syme Thomas Richard Archer Briggs | Botanical Exchange Club Charles Bailey | 9/1879 | MANCH |
| Rumex conglomeratus x pulcher = R. x muretii | GB, VC2 East Cornwall, Torpoint Cultivated | John Thomas Irvine Boswell-Syme Thomas Richard Archer Briggs | Botanical Exchange Club of The British Isles Charles Bailey | 9/1879 | 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 |
| Linaria supina | GB, VC3 South Devon, Cattedown | G Lawson | George Lloyd Botanical Society of London John Thomas Irvine Boswell-Syme | 7/1850 | K |
| Linaria supina | GB, VC3 South Devon, Cattedown | G Lawson | George Cheetham Churchill John Thomas Irvine Boswell-Syme | 7/1850 | K |
| Carex rostrata | GB, VC3 South Devon, Dartmoor | Thomas Richard Archer Briggs | Frederick Janson Hanbury John Thomas Irvine Boswell-Syme | 30/6/1868 | BM |
| Carex muricata | GB, VC3 South Devon, Plymouth | Isaiah Waterloo Nicholson Keys | Frederick Janson Hanbury John Thomas Irvine Boswell-Syme | 21/5/1846 | BM |
| Carex divulsa subsp. divulsa | GB, VC6 North Somerset, Bath | Christopher Edmund Broome | John Thomas Irvine Boswell-Syme Frederick Janson Hanbury | 6/1867 | BM |
| Carex divulsa subsp. divulsa | GB, VC6 North Somerset, Bath | Robert Withers | John Thomas Irvine Boswell-Syme Robert Withers | | BM |
| Carex divulsa subsp. divulsa | GB, VC6 North Somerset, Chew Magna | John Firminger Duthie | Frederick Janson Hanbury John Thomas Irvine Boswell-Syme | 16/6/1879 | BM |
| Carex disticha | GB, VC8 South Wiltshire, Stapleford | William Moyle Rogers | John Thomas Irvine Boswell-Syme | 6/1876 to 9/1876 | BM |
| Carex arenaria | GB, VC9 Dorset, Chesil Bank | John Thomas Irvine Boswell-Syme | John Thomas Irvine Boswell-Syme | 8/1866 | BM |
| Suaeda vera | GB, VC9 Dorset, Chesil Beach | John Thomas Irvine Boswell-Syme | Augustin Ley | 8/1866 | BIRM |
| Limonium binervosum | GB, VC9 Dorset, Portland | John Thomas Irvine Boswell-Syme | William Hadden Beeby | 8/1866 | SLBI |
| Clematis vitalba | GB, VC10 Isle of Wight | John Thomas Irvine Boswell-Syme | Botanical Exchange Club of the Thirsk Natural History Society Charles Bailey John Ray Hardy | 1850 | MANCH |
+ | Peucedanum ostruthium | GB, VC10 Isle of Wight | John Thomas Irvine Boswell-Syme | Manchester Free Reference Library Windsor Collection John Windsor | | MANCH |
| Carex divisa | GB, VC10 Isle of Wight, Bembridge | Alexander Goodman More | Frederick Janson Hanbury John Thomas Irvine Boswell-Syme | 7/1852 | BM |
| Carex divisa | GB, VC10 Isle of Wight, Binstead | John Firminger Duthie | John Thomas Irvine Boswell-Syme Frederick Janson Hanbury | 30/5/1870 | BM |
| Carex otrubae x remota = C. x pseudoaxillaris | GB, VC10 Isle of Wight, Binstead | | John Thomas Irvine Boswell-Syme | 6/1858 | BM |
| Carex divulsa subsp. divulsa | GB, VC10 Isle of Wight, Cowes | John Thomas Irvine Boswell-Syme | Botanical Society of London Eric Frederic Drabble Hilda Lake Drabble | 8/1850 | BM |
| Carex divisa | GB, VC10 Isle of Wight, Isle of Wight | Frederic Stratton | Frederick Janson Hanbury John Thomas Irvine Boswell-Syme | 23/7/1869 | BM |
| Carex paniculata x remota = C. x boenninghauseniana | GB, VC10 Isle of Wight, Isle of Wight | Frederic Stratton | Frederic Stratton John Thomas Irvine Boswell-Syme | 29/7/1872 | BM |
| Carex paniculata x remota = C. x boenninghauseniana | GB, VC10 Isle of Wight, Newchurch | Frederic Stratton | John Thomas Irvine Boswell-Syme | 29/7/1872 | BM |
| Carex divulsa subsp. divulsa | GB, VC10 Isle of Wight, Newport | John Thomas Irvine Boswell-Syme | Frederick Janson Hanbury John Thomas Irvine Boswell-Syme | 9/1867 | BM |
| Cyperus longus | GB, VC10 Isle of Wight, Niton | John Thomas Irvine Boswell-Syme | Augustin Ley | 9/1850 | BIRM |
+ | Mentha suaveolens x longifolia = M. x rotundifolia | GB, VC10 Isle of Wight, Niton | John Thomas Irvine Boswell-Syme | Charles Bailey | 8/1850 | MANCH |
| Carex otrubae x remota = C. x pseudoaxillaris | GB, VC10 Isle of Wight, Quarr | | John Thomas Irvine Boswell-Syme | 6/1858 | BM |
| Carex otrubae x remota = C. x pseudoaxillaris | GB, VC10 Isle of Wight, Quarr | Alexander Goodman More | John Thomas Irvine Boswell-Syme | | BM |
| Carex divisa | GB, VC10 Isle of Wight, Ryde | Thomas Bell Salter | Frederick Janson Hanbury John Thomas Irvine Boswell-Syme Thomas Bell Salter | 5/1840 | BM |
| Carex divisa | GB, VC10 Isle of Wight, Saint Helen's Spit | Alexander Goodman More | John Thomas Irvine Boswell-Syme Frederick Janson Hanbury | 6/1858 | BM |
| Carex arenaria | GB, VC11 South Hampshire, Southsea | Daniel Chambers MacReight | Frederick Janson Hanbury John Thomas Irvine Boswell-Syme | 8/1836 | BM |
| Carex acutiformis | GB, VC12 North Hampshire, Basingstoke | Hewett Cottrell Watson | Frederick Janson Hanbury Hewett Cottrell Watson John Thomas Irvine Boswell-Syme | 1866 | BM |
| Carex disticha | GB, VC12 North Hampshire, Basingstoke | Hewett Cottrell Watson | Frederick Janson Hanbury John Thomas Irvine Boswell-Syme | 1866 | BM |
| Carex ovalis | GB, VC12 North Hampshire, Liss | Frederick Townsend | Frederick Townsend John Thomas Irvine Boswell-Syme Frederick Janson Hanbury | 6/1873 | BM |
| Carex divulsa subsp. divulsa | GB, VC13 West Sussex, Chichester | John Thomas Irvine Boswell-Syme | Frederick Janson Hanbury John Thomas Irvine Boswell-Syme | 9/9/1842 | BM |
| Carex muricata | GB, VC13 West Sussex, Chichester | | Frederick Janson Hanbury John Thomas Irvine Boswell-Syme | 24/5/1843 | BM |