| Mentha arvensis x aquatica = M. x verticillata | GB, VC6 North Somerset, Bath | Charles Cardale Babington | John Stevens Henslow | 9/1833 | CGE |
| Mentha arvensis x aquatica = M. x verticillata | GB, VC29 Cambridgeshire, Madingley | John Stevens Henslow | John Stevens Henslow | 31/7/1828 | CGE |
| Mentha arvensis x aquatica = M. x verticillata | GB, VC59 South Lancashire, Warrington | William Wilson | John Stevens Henslow | 8/1824 | CGE |
| Mentha arvensis x aquatica x spicata = M. x smithiana | GB, VC58 Cheshire, Newchurch | William Wilson | John Stevens Henslow | 11/1826 | CGE |
| Mentha arvensis x aquatica x spicata = M. x smithiana | GB, VC64 Mid-west Yorkshire, Ripon | Samuel Hailstone | John Stevens Henslow | | CGE |
| Mentha arvensis x aquatica x spicata = M. x smithiana | GB, VC64 Mid-west Yorkshire, Settle | John Howson | John Stevens Henslow | 8/1833 | CGE |
| Mentha arvensis x aquatica x spicata = M. x smithiana | GB, VC64 Mid-west Yorkshire, Settle | John Howson | John Stevens Henslow | 8/1833 | CGE |
| Mentha arvensis x spicata = M. x gracilis | GB, VC39 Staffordshire, Tutbury | Charles Cardale Babington | John Stevens Henslow | 10/9/1832 | CGE |
| Mentha arvensis x spicata = M. x gracilis | GB, VC40 Shropshire | Bell Edward Williams | John Stevens Henslow | | CGE |
| Mentha arvensis x spicata = M. x gracilis | GB, VC59 South Lancashire, Warrington | William Wilson | John Stevens Henslow | 8/1824 | CGE |
| Mentha arvensis x spicata = M. x gracilis | GB, VC83 Midlothian, Roslin | John Hutton Balfour | John Stevens Henslow | 9/1835 | CGE |
+ | Minuartia hybrida | GB, VC29 Cambridgeshire, Gog Magog Hills | John Stevens Henslow | Warrington Museum William Wilson | 2/6/1825 | MANCH |
+ | Minuartia hybrida | GB, VC29 Cambridgeshire, Gog Magog Hills | John Stevens Henslow | John Hutton Balfour | 24/5/1834 | PTH |
+ | Moenchia erecta | GB, VC14 East Sussex, Hastings | John Stevens Henslow | John Hutton Balfour | 1836 | PTH |
| Molinia caerulea | GB, VC90 Angus, Clova Mountains | Graham Robert Kaye Greville | John Stevens Henslow | 1832 | BIRM |
+ | Monotropa hypopitys | GB, VC22 Berkshire, Cholsey | John Stevens Henslow | Bowman | 7/1835 | MANCH |
+ | Nepeta cataria | GB, VC16 West Kent, Wilmington | John Stevens Henslow | Charles Bailey John Stevens Henslow | 1838 | MANCH |
+ | Onobrychis viciifolia | GB, VC29 Cambridgeshire, Newmarket, Devils Ditch | John Stevens Henslow | | 20/6/1826 | MANCH |
+ | Otanthus maritimus | GB, VC25 East Suffolk, Dunwich | John Stevens Henslow | Warrington Museum William Wilson | 7/8/1829 | MANCH |
+ | Peucedanum palustre | GB, VC29 Cambridgeshire, Burwell Fen | John Stevens Henslow | John Hutton Balfour | 19/8/1831 | PTH |
| Phalaris paradoxa | GB, VC9 Dorset, Isle of Purbeck | I Austen | John Stevens Henslow | | BIRM |
| Poa alpina | GB, VC49 Caernarvonshire, Snowdon | E Holmes | John Stevens Henslow | 7/1832 | BIRM |
| Poa alpina | GB, VC90 Angus, Glen Isla | Robert Kaye Greville | John Stevens Henslow | 1832 | BIRM |
| Potamogeton coloratus x berchtoldii = P. x lanceolatus | GB, VC52 Anglesey, Anglesey | John Stevens Henslow | John Stevens Henslow | 1826 | E |
+ | Potentilla argentea | GB, VC27 East Norfolk | John Stevens Henslow | Warrington Museum William Wilson | 7/1824 | MANCH |
| Primula elatior | GB, Suffolk | John Stevens Henslow | Allan Octavian Hume Frederick Townsend | 5/1845 | SLBI |
+ | Pulicaria vulgaris | GB, VC18 South Essex, Downham | John Stevens Henslow | Warrington Museum William Wilson | 18/8/1827 | MANCH |
+ | Pulsatilla vulgaris | GB, VC29 Cambridgeshire, Bartlow | John Stevens Henslow | Warrington Museum William Wilson | 8/8/1826 | MANCH |
| Pulsatilla vulgaris | GB, VC29 Cambridgeshire, Cambridge | John Stevens Henslow William Strong Hore | John Ralfs | 1838 | SLBI |
+ | Pulsatilla vulgaris | GB, VC29 Cambridgeshire, Gog Magog Hills | John Stevens Henslow | John Hutton Balfour | 5/5/1835 | PTH |
+ | Pulsatilla vulgaris | GB, VC29 Cambridgeshire, Gog Magog Hills | John Stevens Henslow | William Wilson | 28/4/1830 | MANCH |
| Pyrola minor | GB, VC65 North-west Yorkshire, Richmond | John Stevens Henslow | John Eddowes Bowman | | MANCH |
+ | Roemeria hybrida | GB, VC29 Cambridgeshire, Cambridge | John Stevens Henslow | John Hutton Balfour | 1835 | PTH |
+ | Roemeria hybrida | GB, VC29 Cambridgeshire, Reach | John Stevens Henslow | John Hutton Balfour | 6/1828 | PTH |
+ | Roemeria hybrida | GB, VC29 Cambridgeshire, Reach | John Stevens Henslow | John Hutton Balfour | 6/1828 | PTH |
| Salix arbuscula | GB, VC98 Argyllshire, Ben Cruachan | J Hooker | John Stevens Henslow | | BIRM |
| Salix fragilis x alba = S. x rubens | GB, VC65 North-west Yorkshire, Easby | James Ward | John Stevens Henslow | 4/5/1842 16/7/1842 | CGE |
| Salix viminalis x caprea = S. x smithiana | GB, VC19 North Essex, Audley End | John Ewbank Leefe | John Stevens Henslow | 7/5/1842 | CGE |
| Salix viminalis x caprea = S. x smithiana | GB, VC19 North Essex, Audley End | John Ewbank Leefe | John Stevens Henslow | 19/3/1842 19/7/1842 | CGE |
| Salix viminalis x caprea = S. x smithiana | GB, VC65 North-west Yorkshire, Richmond | James Ward | John Stevens Henslow | 25/3/1842 9/4/1842 22/4/1842 21/6/1842 9/7/1842 23/7/1842 | CGE |