| Puccinellia distans | GB, VC13 West Sussex, Chichester | William Williamson Newbould | William Hillhouse | 1842 | BIRM |
| Bromus commutatus | GB, VC21 Middlesex, Acton | William Williamson Newbould | Augustin Ley | 6/1867 | BIRM |
| Viola | GB, VC29 Cambridgeshire, Cambridge | Charles Cardale Babington William Henry Purchas William Williamson Newbould | Augustin Ley | 1857 | BIRM |
| Thymus chamaedrys | GB, VC29 Cambridgeshire, Harlton | William Williamson Newbould | Charles Cardale Babington George Stephen West | 1/7/1853 | BIRM |
| Fumaria muralis | GB, VC63 South-west Yorkshire, Sheffield | William Williamson Newbould | Charles Cardale Babington George Stephen West | 29/7/1859 | BIRM |
| Carex echinata | GB, VC5 South Somerset, Dunkery Hill | William Williamson Newbould | | 7/2/1850 | BM |
| Carex muricata subsp. pairae | GB, VC5 South Somerset, Dunster | William Williamson Newbould | | 25/6/1850 | BM |
| Carex divisa | GB, VC10 Isle of Wight, Gurnard Bay | Frederick Townsend | Frederick Townsend William Williamson Newbould | 6/1844 | BM |
| Carex vulpina | GB, VC13 West Sussex, Chichester | | John Thomas Irvine Boswell-Syme William Williamson Newbould | 6/1843 | BM |
| Carex pseudocyperus | GB, VC15 East Kent, Sandwich | William Williamson Newbould | John Thomas Irvine Boswell-Syme Frederick Janson Hanbury | 20/7/1843 | BM |
| Carex otrubae x remota = C. x pseudoaxillaris | GB, VC19 North Essex, Inworth | Ezekiel George Varenne | William Williamson Newbould | 7/1847 | BM |
| Carex remota | GB, VC20 Hertfordshire, Buntingford | William Williamson Newbould | William Williamson Newbould | 3/8/1847 | 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 riparia | 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 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 spicata | GB, VC29 Cambridgeshire, Thriplow | William Williamson Newbould | Frederick Janson Hanbury John Thomas Irvine Boswell-Syme | 28/5/1847 | BM |
| Carex lasiocarpa | GB, VC29 Cambridgeshire, Wicken Fen | William Williamson Newbould | | 15/7/1851 | BM |
| Carex riparia | GB, VC31 Huntingdonshire, Somersham | William Williamson Newbould | Frederick Janson Hanbury John Thomas Irvine Boswell-Syme | 6/1846 | BM |
| Carex canescens | GB, VC59 South Lancashire, White Moss | Leopold Hartley Grindon | William Williamson Newbould | 6/1841 | BM |
| Carex leporina | GB, VC63 South-west Yorkshire, Aldwarke | | John Thomas Irvine Boswell-Syme William Williamson Newbould | | 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 lasiocarpa | GB, VC108 West Sutherland, Glen Canish | | John Thomas Irvine Boswell-Syme Nicholas Tyacke William Williamson Newbould Frederick Janson Hanbury | | BM |
| Carex maritima | GB, VC108 West Sutherland, Polin | | William Williamson Newbould | | BM |
| Mentha aquatica x spicata = M. x piperita | GB, VC29 Cambridgeshire, Barrington | William Williamson Newbould | | 9/9/1856 | CGE |
| Carex flacca | GB, VC13 West Sussex, Mundham | William Williamson Newbould | | 1843 | E |
| Silene conica | GB, VC15 East Kent, Sandwich | William Williamson Newbould | | 8/1843 | K |
+ | Mentha pulegium | GB, Hampshire, River Erith | William Williamson Newbould | John Ray Hardy Susannah Mary Payne | 1841 | MANCH |
+ | Euphorbia exserta | GB, VC13 West Sussex, Chichester | William Williamson Newbould | John Hardy | 10/1843 | MANCH |
| Potamogeton polygonifolius | GB, VC13 West Sussex, Chichester | William Williamson Newbould | John Hardy | 10/1843 | MANCH |
+ | Neottia nidus-avis | GB, VC13 West Sussex, Goodwood | William Williamson Newbould | John Ray Hardy | 6/1843 | MANCH |
+ | Vicia lutea | GB, VC13 West Sussex, Shoreham | | William Williamson Newbould | 5/7/1832 | MANCH |
| Carex pseudocyperus | GB, VC15 East Kent, Ramsgate | William Williamson Newbould | Charles Bailey John Hardy | 24/7/1843 | MANCH |
+ | Medicago minima | GB, VC15 East Kent, Ramsgate,Pegwell Bay | William Williamson Newbould | Charles Bailey John Hardy | 7/1843 | MANCH |
+ | Silene conica | GB, VC15 East Kent, Ramsgate,Pegwell Bay | William Williamson Newbould | Charles Bailey John Ray Hardy | 20/7/1882 | MANCH |
| Rumex crispus x obtusifolius = R. x pratensis | GB, VC20 Hertfordshire, Broxbourne | William Williamson Newbould | Charles Bailey William Williamson Newbould | 19/7/1848 | MANCH |