| 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 |
+ | Astragalus danicus | GB, VC83 Midlothian, Edinburgh,Arthur's Seat | | Charles Bailey Henry Alexander Hurst William Williamson Newbould | 5/1830 | MANCH |
| Ballota nigra | GB, VC31 Huntingdonshire, Bluntisham | William Williamson Newbould | Frederick Townsend | 3/9/1846 | SLBI |
| Bromus commutatus | GB, VC21 Middlesex, Acton | William Williamson Newbould | Augustin Ley | 6/1867 | BIRM |
+ | Bromus secalinus | GB, VC21 Middlesex, Brentford | William Williamson Newbould | Charles Bailey | 6/1867 | MANCH |
+ | Bupleurum rotundifolium | GB, VC29 Cambridgeshire, Upware | William Williamson Newbould | Charles Bailey | 14/7/1856 | MANCH |
| Butomus umbellatus | GB, VC31 Huntingdonshire, Bluntisham | William Williamson Newbould | John Hardy | 7/1845 | MANCH |
+ | Carex appropinquata | GB, VC61 South-east Yorkshire, Heslington Fields | William Williamson Newbould | Charles Bailey John Hardy | 7/2/1846 | MANCH |
| Carex canescens | GB, VC59 South Lancashire, White Moss | Leopold Hartley Grindon | William Williamson Newbould | 6/1841 | BM |
| Carex chordorrhiza | GB, VC77,VC78,VC83, Pentland Hills | Nicholas Tyacke | John Thomas Irvine Boswell-Syme William Williamson Newbould | 1843 | BM |
| Carex diandra | GB, VC90 Angus, Rescobie | Andrew Kerr | Botanical Society of Edinburgh William Williamson Newbould | 7/1841 | BM |
| Carex divisa | GB, VC10 Isle of Wight, Gurnard Bay | Frederick Townsend | Frederick Townsend William Williamson Newbould | 6/1844 | BM |
| Carex divisa | GB, VC25 East Suffolk, Walton | William Williamson Newbould | William Williamson Newbould | 8/1864 | BM |
| Carex divisa | GB, VC27 East Norfolk, Yarmouth | William Williamson Newbould | | 7/7/1847 | BM |
| Carex echinata | GB, VC5 South Somerset, Dunkery Hill | William Williamson Newbould | | 7/2/1850 | BM |
| Carex flacca | GB, VC13 West Sussex, Mundham | William Williamson Newbould | | 1843 | E |
| Carex lasiocarpa | GB, VC29 Cambridgeshire, Wicken Fen | William Williamson Newbould | | 15/7/1851 | BM |
| Carex lasiocarpa | GB, VC108 West Sutherland, Glen Canish | | John Thomas Irvine Boswell-Syme Nicholas Tyacke William Williamson Newbould Frederick Janson Hanbury | | BM |
| Carex leporina | GB, VC63 South-west Yorkshire, Aldwarke | | John Thomas Irvine Boswell-Syme William Williamson Newbould | | BM |
| Carex maritima | GB, VC108 West Sutherland, Polin | | William Williamson Newbould | | BM |
| Carex muricata subsp. pairae | GB, VC5 South Somerset, Dunster | William Williamson Newbould | | 25/6/1850 | BM |
| Carex otrubae x remota = C. x pseudoaxillaris | GB, VC19 North Essex, Inworth | Ezekiel George Varenne | William Williamson Newbould | 7/1847 | BM |
| Carex otrubae x remota = C. x pseudoaxillaris | GB, VC20 Hertfordshire, Buntingford | William Williamson Newbould | | 21/7/1848 | BM |
| Carex otrubae x remota = C. x pseudoaxillaris | GB, VC20 Hertfordshire, Layston | William Williamson Newbould | | | BM |
| Carex paniculata | GB, VC21 Middlesex, Willesden | William Williamson Newbould | John Thomas Irvine Boswell-Syme | 7/1867 | BM |
| Carex paniculata | GB, VC25 East Suffolk, Belton Fen | William Williamson Newbould | | 8/6/1847 | BM |
| Carex pseudocyperus | GB, VC15 East Kent, Ramsgate | William Williamson Newbould | Charles Bailey John Hardy | 24/7/1843 | MANCH |
| Carex pseudocyperus | GB, VC15 East Kent, Sandwich | William Williamson Newbould | John Thomas Irvine Boswell-Syme Frederick Janson Hanbury | 20/7/1843 | BM |
| Carex remota | GB, VC20 Hertfordshire, Buntingford | William Williamson Newbould | William Williamson Newbould | 3/8/1847 | BM |
| Carex remota x vulpina = C. axilaris | GB, VC20 Hertfordshire, Buntingford | William Williamson Newbould | Allan Octavian Hume Frederick Townsend | 21/7/1848 | SLBI |
| Carex riparia | GB, VC21 Middlesex, Willesden | William Williamson Newbould | John Thomas Irvine Boswell-Syme | 7/1867 | BM |
| Carex riparia | GB, VC31 Huntingdonshire, Somersham | William Williamson Newbould | Frederick Janson Hanbury John Thomas Irvine Boswell-Syme | 6/1846 | BM |