| Achillea maritima | GB, VC113 Channel Islands, Jersey, Saint Ouen's | William Williamson Newbould | Frederick Townsend | 9/7/1862 | SLBI |
| Aethusa cynapium subsp. agrestis | GB, VC13 West Sussex, Chichester | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 10/1843 | SLBI |
| Allium oleraceum | Vaud, Pais de Bey | William Williamson Newbould | Allan Octavian Hume | | SLBI |
| Allium oleraceum | GB, VC29 Cambridgeshire, Barton | William Williamson Newbould | | 1850 | SLBI |
| Allium oleraceum | GB, VC29 Cambridgeshire, Barton | William Williamson Newbould | Allan Octavian Hume | 1850 | SLBI |
| Apium inundatum | GB, VC113 Channel Islands, Jersey, Noirmont Point | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 20/8/1842 | SLBI |
| Arctium nemorosum | GB, VC17 Surrey, Surbiton | William Williamson Newbould | William Hadden Beeby | 8/1883 | SLBI |
| Armeria arenaria | GB, VC113 Channel Islands, Jersey, Quennevais | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 9/1842 | SLBI |
| Asparagus officinalis | GB, VC1 West Cornwall, Lizard | William Williamson Newbould | | 8/1874 | SLBI |
| Ballota nigra | GB, VC31 Huntingdonshire, Bluntisham | William Williamson Newbould | Frederick Townsend | 3/9/1846 | SLBI |
| Carex remota x vulpina = C. axilaris | GB, VC20 Hertfordshire, Buntingford | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 21/7/1848 | SLBI |
| Caucalis platycarpos | GB, VC29 Cambridgeshire, Harston | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 17/7/1848 | SLBI |
| Centaurea nigra | GB, VC61,VC62,VC64, York | William Williamson Newbould | Frederick Townsend William Williamson Newbould | 1/7/1846 | SLBI |
| Cephalanthera longifolia | GB, VC13 West Sussex, Goodwood | William Williamson Newbould | Allan Octavian Hume Frederick Townsend William Williamson Newbould | 6/10/1843 | SLBI |
| Cephalanthera longifolia | GB, VC13 West Sussex, Goodwood | William Williamson Newbould | | 6/1843 | SLBI |
| Cerastium fontanum subsp. vulgare | GB, VC29 Cambridgeshire, Gamlingay | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 5/4/1849 | SLBI |
| Cirsium heterophyllum | GB, VC57 Derbyshire, Hathersage | William Williamson Newbould | Frederick Townsend | 1846 | SLBI |
| Crepis foetida | GB, VC26 West Suffolk, Brandon | William Williamson Newbould | Frederick Townsend | 4/7/1848 | SLBI |
| Cuscuta epithymum | GB, VC29 Cambridgeshire, Whittlesford | Parnell William Williamson Newbould | Frederick Townsend | | SLBI |
| Cuscuta europaea | GB, VC29 Cambridgeshire, Waterford | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | | SLBI |
| Dianthus armeria | GB, VC13 West Sussex, Chichester | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 10/1843 | SLBI |
| Dipsacus fullonum | GB, VC13 West Sussex, Chichester | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 1843 | SLBI |
| Dipsacus fullonum | GB, VC31 Huntingdonshire, Colne | William Williamson Newbould | Frederick Townsend | 1845 | SLBI |
| Epipactis phyllanthes | GB, VC20 Hertfordshire, Buntingford, Throcking | William Williamson Newbould | Frederick Townsend | 8/4/1847 | SLBI |
| Erica mackaiana | IE, VCH16 West Galway, Roundstone | William Williamson Newbould | | 5/1880 | SLBI |
| Eriophorum latifolium | GB, VC97 West Inverness-shire, Arisaig | Nicholas Tyacke William Williamson Newbould | Frederick Townsend | | SLBI |
| Euphorbia hyberna | GB, VC4 North Devon, Linton | William Williamson Newbould | | 6/1850 | SLBI |
| Euphorbia hyberna | GB, VC4 North Devon, Lynton | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 6/1850 | SLBI |
| Euphorbia platyphyllos | GB, VC29 Cambridgeshire, Toft | William Williamson Newbould | Frederick Townsend | | SLBI |
| Galium album | GB, VC29 Cambridgeshire, Eversden | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 14/6/1848 | SLBI |
| Gnaphalium luteoalbum | GB, VC113 Channel Islands, Saint Ouen's Bay, Jersey | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 22/8/1842 | SLBI |
| Hammarbya paludosa | GB, VC87 West Perthshire, Inverarnan | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 8/4/1846 | SLBI |
| Heracleum sphondylium | GB, VC31 Huntingdonshire, Bluntisham | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 3/10/1846 | SLBI |
| Hieracium strictiforme | GB, Mid-West Perthshire, Glen Falloch | Charles Cardale Babington William Williamson Newbould | Frederick Townsend | 5/8/1846 | SLBI |
| Lamium album | GB, VC17 Surrey, Kew | William Williamson Newbould | William Hadden Beeby | 5/1885 | SLBI |
| Lamium maculatum | GB, VC63 South-west Yorkshire, Sheffield | William Williamson Newbould | Frederick Townsend | 18/7/1846 | SLBI |
| Lathyrus aphaca | GB, VC29 Cambridgeshire, Cherry Hinton | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | | SLBI |
| Lathyrus japonicus subsp. maritimus | GB, VC15 East Kent, Walmer Castle | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 7/1843 | SLBI |
| Lathyrus japonicus subsp. maritimus | GB, VC15 East Kent, Walmer Castle | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 8/1843 | SLBI |
| Lathyrus sylvestris | GB, VC41 Glamorganshire, Caswell Bay | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 12/8/1848 | SLBI |