+ | Bupleurum tenuissimum | GB, VC18 South Essex, Tilbury | John Norton Mills John Patrick Micklethwait Brenan | John Norton Mills | 2/9/1944 | MANCH |
+ | Bupleurum tenuissimum | GB, VC18 South Essex, Tilbury | John Norton Mills John Patrick Micklethwait Brenan | John Norton Mills | 2/9/1944 | MANCH |
+ | Leucanthemum lacustre x maximum = L. x superbum | GB, VC59 South Lancashire, Birkdale | John Norton Mills John Patrick Micklethwait Brenan | John Norton Mills | 28/7/1959 | MANCH |
| Myriophyllum verticillatum | GB, VC30 Bedfordshire, Eaton Socon | John Frederick Gustav Chapple John Patrick Micklethwait Brenan | Druce Herbarium, Oxford | 11/8/1946 | SLBI |
| Ballota nigra var. borealis | GB, VC41 Glamorganshire, Kenfig | John Patrick Micklethwait Brenan | | 13/9/1945 | K |
| Blysmus compressus | GB, VC6 North Somerset, Shepton Mallet | John Patrick Micklethwait Brenan Richard Alexander Fraser Brenan | | 12/6/1969 | K |
| Blysmus compressus | GB, VC20 Hertfordshire, Oughtonhead Common | John Patrick Micklethwait Brenan | | 26/6/1955 | K |
| Bupleurum tenuissimum | GB, VC11 South Hampshire, Hayling Island | John Patrick Micklethwait Brenan | | 1/10/1936 | K |
| Bupleurum tenuissimum | GB, VC18 South Essex, Tilbury | John Patrick Micklethwait Brenan | | 2/9/1944 | K |
| Callitriche intermedia subsp. hamulata | GB, VC16 West Kent, Snodland | John Patrick Micklethwait Brenan | | 28/5/1936 | K |
| Callitriche intermedia subsp. hamulata | GB, VC14 East Sussex, Chailey Common | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 23/5/1936 | K |
| Callitriche obtusangula | GB, VC4 North Devon, Appledore | John Patrick Micklethwait Brenan | | 21/5/1936 | K |
| Callitriche stagnalis | GB, VC30 Bedfordshire, Flitwick | Edgar Wolston Bertram Handsley Milne-Redhead John Patrick Micklethwait Brenan | | 21/7/1946 | K |
| Callitriche stagnalis | GB, VC17 Surrey, Godalming | John Patrick Micklethwait Brenan | | 25/5/1935 | K |
| Callitriche stagnalis | GB, VC2 East Cornwall, Fowey | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 16/6/1949 | K |
| Callitriche stagnalis | GB, VC30 Bedfordshire, Flitwick | Edgar Wolston Bertram Handsley Milne-Redhead John Patrick Micklethwait Brenan | | 1/7/1946 | K |
| Callitriche stagnalis | GB, VC6 North Somerset, Cheddar | John Patrick Micklethwait Brenan | | 8/9/1936 | K |
| Callitriche truncata | GB, VC5 South Somerset, Taunton | John Patrick Micklethwait Brenan | | 8/9/1936 | K |
| Callitriche truncata | GB, VC16 West Kent, Chipstead | John Patrick Micklethwait Brenan | | 10/7/1935 | K |
| Carex divulsa | GB, VC29 Cambridgeshire, Cott Farm | John Patrick Micklethwait Brenan | Botanical Society of The British Isles John Patrick Micklethwait Brenan Martin F Gardner & Sabina G Knees | 29/5/1948 | E |
| Carex hirta | GB, VC23 Oxfordshire, Oxford | | John Patrick Micklethwait Brenan | 3/6/1936 | BM |
| Crepis mollis | GB, VC66 County Durham, River Tees at High Force | John Patrick Micklethwait Brenan N S G C | John Patrick Micklethwait Brenan | 19/7/1938 | K |
| Cuscuta epithymum | GB, VC15 East Kent, Dungeness | John Patrick Micklethwait Brenan Noel Yvri Sandwith | | 20/9/1936 | K |
| Dactylis glomerata | GB, VC28 West Norfolk, Appleton | Charles Edward Hubbard | John Patrick Micklethwait Brenan | 12/7/1935 | K |
| Dactylis glomerata | GB, VC46 Cardiganshire, Cae Melyn | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 19/6/1942 | K |
| Dactylis glomerata | GB, VC6 North Somerset, Shepton Mallet | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 9/7/1944 | K |
| Dactylis glomerata | GB, VC16 West Kent, Snodland | John Patrick Micklethwait Brenan | | 28/5/1936 | K |
| Dactylis glomerata | GB, VC35 Monmouthshire, Wern Fawr | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 9/6/1942 | K |
| Dactylis glomerata | GB, VC6 North Somerset, Shepton Mallet | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 6/9/1942 | K |
| Draba muralis | GB, VC6 North Somerset, Easton-in-Gordano | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 20/4/1935 | SLBI |
| Fallopia dumetorum | GB, VC17 Surrey, Wimbledon Common | John Patrick Micklethwait Brenan Noel Yvri Sandwith | John Patrick Micklethwait Brenan | 10/1948 | K |
| Festuca arundinacea | GB, VC2 East Cornwall, Portscatho | John Patrick Micklethwait Brenan Richard Alexander Fraser Brenan | | 23/6/1949 | K |
| Glebionis segetum | GB, VC16 West Kent, Sevenoaks | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 12/9/1937 | K |
| Glebionis segetum | GB, VC16 West Kent, Sevenoaks | John Patrick Micklethwait Brenan | | 19/7/1936 | K |
| Glebionis segetum | GB, VC18 South Essex, Dagenham | John Patrick Micklethwait Brenan | | 30/8/1936 | K |
| Glebionis segetum | GB, VC16 West Kent, Tunbridge | John Patrick Micklethwait Brenan | | 28/6/1936 | K |
| Glebionis segetum | GB, VC35 Monmouthshire, Chepstow | John Patrick Micklethwait Brenan | | 11/9/1935 | K |
| Glechoma hederacea | GB, VC17 Surrey, Wisley | John Patrick Micklethwait Brenan Noel Yvri Sandwith | John Patrick Micklethwait Brenan | 6/4/1946 | K |
| Glechoma hederacea | GB, VC1 West Cornwall, Ponsanooth | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 26/3/1937 | K |
| Glechoma hederacea | GB, VC16 West Kent, Tonbridge | John Patrick Micklethwait Brenan | | 5/4/1935 | K |