+ | Ranunculus | GB, VC29 Cambridgeshire, Haddenham | William Williamson Newbould | Charles Bailey John Ray Hardy | 6/9/1846 | MANCH |
| Ranunculus baudotii | GB, VC28 West Norfolk, Burnham Norton | William Williamson Newbould | Allan Octavian Hume Charles Cardale Babington Frederick Townsend | 24/5/1852 | SLBI |
| Ranunculus parviflorus | GB, VC29 Cambridgeshire, Comberton | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | | SLBI |
| Rubus latifolius | GB, VC83 Midlothian, Cramond Bridge | William Williamson Newbould | | 8/11/1846 | SLBI |
| Rubus latifolius | GB, VC83 Midlothian, Edinburgh | William Williamson Newbould | | 1846 | SLBI |
| Rumex crispus subsp. elongatus | | | Frederick Townsend William Williamson Newbould | 5/7/1873 | SLBI |
| Rumex crispus x obtusifolius = R. x pratensis | GB, VC19 North Essex, Broxbourne | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 19/7/1848 | SLBI |
| Rumex crispus x obtusifolius = R. x pratensis | GB, VC20 Hertfordshire, Broxbourne | William Williamson Newbould | Charles Bailey William Williamson Newbould | 19/7/1848 | MANCH |
| Rumex maritimus | GB, VC31 Huntingdonshire, Bluntisham | William Williamson Newbould | Frederick Townsend | 13/9/1845 | SLBI |
| Rumex maritimus | GB, VC31 Huntingdonshire, Holme Fen | William Williamson Newbould | Frederick Townsend | 16/9/1845 | SLBI |
| Rumex obtusifolius var. sylvestris | GB, VC17,VC21, Putney | William Williamson Newbould | Frederick Townsend | | SLBI |
| Ruppia rostellata | GB, VC13 West Sussex, Chichester | William Williamson Newbould | Frederick Townsend | 9/1844 | SLBI |
| Sagittaria sagittifolia | GB, VC13 West Sussex, Chichester | William Williamson Newbould | Frederick Townsend | 10/1846 | SLBI |
| Sagittaria sagittifolia | GB, VC31 Huntingdonshire, Bluntisham | William Williamson Newbould | Frederick Townsend | 5/1845 | SLBI |
+ | Scandix pecten-veneris | GB, VC62 North-east Yorkshire, Whitby,Saltwick Bay | William Williamson Newbould | | 1844 | MANCH |
| Schoenoplectus lacustris | GB, VC31 Huntingdonshire, Bluntisham | William Williamson Newbould | Frederick Townsend | 6/1846 | SLBI |
| Schoenoplectus pungens | GB, VC113 Channel Islands, Saint Ouen's Pond | William Williamson Newbould | Frederick Townsend | 8/1842 | SLBI |
| Scleranthus annuus | GB, VC28 West Norfolk, Thetford | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 4/7/1848 | SLBI |
+ | Scleranthus annuus | GB, VC113 Channel Islands, Sark | William Williamson Newbould | Charles Bailey | 24/8/1842 | MANCH |
| Scrophularia scorodonia | GB, VC113 Channel Islands, Jersey, Saint Peters | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 8/5/1842 | SLBI |
| Scrophularia umbrosa | GB, VC83 Midlothian, Cramond Bridge | William Williamson Newbould | Frederick Townsend | 8/11/1846 | SLBI |
+ | Silene conica | GB, VC15 East Kent, Ramsgate,Pegwell Bay | William Williamson Newbould | Charles Bailey John Ray Hardy | 20/7/1882 | MANCH |
| Silene conica | GB, VC15 East Kent, Sandwich | William Williamson Newbould | | 8/1843 | K |
| Silene noctiflora | GB, VC29 Cambridgeshire, Chippenham | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 29/7/1852 | SLBI |
+ | Spiranthes spiralis | GB, VC63 South-west Yorkshire, Doncaster | William Williamson Newbould | Charles Bailey John Ray Hardy | 9/1843 | MANCH |
| Stachys sylvatica | GB, VC13 West Sussex, Chichester | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 1843 | SLBI |
| Stachys sylvatica x palustris = S. x ambigua | GB, VC29 Cambridgeshire, Coton | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 26/7/1844 | SLBI |
| Suaeda maritima | GB, VC13 West Sussex, Chichester | William Williamson Newbould | | 29/9/1843 | SLBI |
+ | Teesdalia nudicaulis | GB, VC29 Cambridgeshire, Gamlingay | William Williamson Newbould | Charles Bailey John Ray Hardy | 3/4/1842 | MANCH |
| Thalictrum minus | GB, VC29 Cambridgeshire, Gog Magog Hills | William Williamson Newbould | | 21/9/1851 | SLBI |
| Thymus chamaedrys | GB, VC29 Cambridgeshire, Harlton | William Williamson Newbould | Charles Cardale Babington George Stephen West | 1/7/1853 | BIRM |
| Trifolium glomeratum | GB, VC113 Channel Islands, Saint Brelade's Bay | William Williamson Newbould | Croydon Natural History and Scientific Society Frederick Townsend | 2/9/1842 | SLBI |
| Trifolium squamosum | GB, VC13 West Sussex, Chichester | William Williamson Newbould | | 7/1846 | SLBI |
| Trifolium squamosum | GB, VC13 West Sussex, Chichester | William Williamson Newbould | | 7/1846 | SLBI |
| Typha angustifolia | GB, VC29 Cambridgeshire, Wicken Fen | William Williamson Newbould | Frederick Townsend | 15/7/1851 | SLBI |
| Urtica pilulifera | GB, VC25 East Suffolk, Lowestoft | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 1854 | SLBI |
+ | Vicia lutea | GB, VC13 West Sussex, Shoreham | | William Williamson Newbould | 5/7/1832 | MANCH |
| Viola | GB, VC29 Cambridgeshire, Cambridge | Charles Cardale Babington William Henry Purchas William Williamson Newbould | Augustin Ley | 1857 | BIRM |
| Viola hirta | GB, VC3 South Devon, Plymouth | Thomas Richard Archer Briggs | George Nicholson William Hadden Beeby William Williamson Newbould | 14/4/1882 | SLBI |
| Viola persicifolia | GB, VC29 Cambridgeshire, Bottisham | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 8/1852 | SLBI |