+ | Tordylium maximum | GB, VC18 South Essex, Tilbury | | John Norton Mills John Patrick Micklethwait Brenan | 27/7/1946 | MANCH |
| Blysmus compressus | GB, VC20 Hertfordshire, Oughtonhead Common | John Patrick Micklethwait Brenan | | 26/6/1955 | K |
| Hypochaeris glabra | GB, VC22 Berkshire, Cothill | John Patrick Micklethwait Brenan | | 5/8/1944 | K |
| Hypochaeris glabra | GB, VC22 Berkshire, Cothill | Alan Philip Dalby Jones John Patrick Micklethwait Brenan | | 5/8/1944 | K |
| Hypochaeris glabra | GB, VC22 Berkshire, Cumnor | E W Jones John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 26/7/1948 | K |
| Plantago lanceolata var. bakeri | GB, VC22 Berkshire, Cumnor | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 3/6/1940 | K |
| Plantago lanceolata var. bakeri | GB, VC22 Berkshire, Cumnor | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 3/6/1940 | K |
| Rumex crispus | GB, VC22 Berkshire, King's Weir | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 11/7/1943 | SLBI |
| Stellaria palustris | GB, VC22 Berkshire, Wytham | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 30/5/1945 | K |
| Mentha spicata x suaveolens = M. x villosa | GB, VC23 Oxfordshire, Freeland | Alan Philip Dalby Jones John Patrick Micklethwait Brenan | | 3/9/1944 | K |
| Ranunculus aquatilis | GB, VC23 Oxfordshire, Menmarsh | John Frederick Gustav Chapple John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 29/4/1937 | SLBI |
| Monotropa hypopitys | GB, VC23 Oxfordshire, Nettlebed | Herbert Kenneth Airy Shaw J S Hughes John Patrick Micklethwait Brenan | | 24/10/1937 | K |
| Carex hirta | GB, VC23 Oxfordshire, Oxford | | John Patrick Micklethwait Brenan | 3/6/1936 | BM |
| Leonurus cardiaca | GB, VC23 Oxfordshire, Oxford | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 21/6/1939 | K |
| Mentha arvensis x aquatica = M. x verticillata | GB, VC23 Oxfordshire, Oxford,Port Meadow | John Patrick Micklethwait Brenan Noel Yvri Sandwith | | 30/8/1941 | K |
| Festuca arundinacea | GB, VC23 Oxfordshire, South Leigh | John Patrick Micklethwait Brenan Ronald Burn | John Patrick Micklethwait Brenan | 30/5/1943 | K |
| Luzula forsteri x pilosa = L. x borreri | GB, VC24 Buckinghamshire, Marlow | John Norton Mills John Patrick Micklethwait Brenan | John Norton Mills | 7/6/1957 | MANCH |
+ | Valerianella dentata | GB, VC25 East Suffolk | J.N.M John Patrick Micklethwait Brenan June R J Mills | | 7/8/1846 | MANCH |
| Dactylis glomerata | GB, VC28 West Norfolk, Appleton | Charles Edward Hubbard | John Patrick Micklethwait Brenan | 12/7/1935 | K |
+ | Limonium binervosum subsp. anglicum | GB, VC28 West Norfolk, Holme-by-the-Sea | John Norton Mills John Patrick Micklethwait Brenan June R J Mills | John Norton Mills | 8/8/1946 | MANCH |
+ | Rumex sanguineus x pulcher = R. x mixtus | GB, VC29 Cambridgeshire, Cambridge | John Norton Mills John Patrick Micklethwait Brenan June R J Mills | John Norton Mills | 4/8/1946 | MANCH |
| 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 |
+ | Melampyrum cristatum | GB, VC29 Cambridgeshire, Hardwick Wood | John Norton Mills John Patrick Micklethwait Brenan | John Norton Mills June R J Mills | 7/8/1946 | MANCH |
+ | Melampyrum cristatum | GB, VC29 Cambridgeshire, Hardwick Wood | John Norton Mills John Patrick Micklethwait Brenan | John Norton Mills June R J Mills | 7/8/1946 | MANCH |
+ | Melampyrum cristatum | GB, VC29 Cambridgeshire, Hardwick Wood | John Norton Mills John Patrick Micklethwait Brenan | John Norton Mills June R J Mills | 7/8/1946 | MANCH |
| Kickxia elatine subsp. elatine | GB, VC29 Cambridgeshire, Newmarket | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 5/8/1946 | K |
+ | Selinum carvifolia | GB, VC29 Cambridgeshire, Newmarket (N of),Chippenham | John Norton Mills John Patrick Micklethwait Brenan June R J Mills | John Norton Mills | 5/8/1946 | MANCH |
+ | Myriophyllum verticillatum | GB, VC30 Bedfordshire | John Norton Mills John Patrick Micklethwait Brenan | Botanical Exchange Club of The British Isles | 11/8/1906 | MANCH |
| Myriophyllum verticillatum | GB, VC30 Bedfordshire, Eaton Socon | John Frederick Gustav Chapple John Patrick Micklethwait Brenan | Druce Herbarium, Oxford | 11/8/1946 | SLBI |
| Callitriche stagnalis | GB, VC30 Bedfordshire, Flitwick | Edgar Wolston Bertram Handsley Milne-Redhead John Patrick Micklethwait Brenan | | 1/7/1946 | K |
| Callitriche stagnalis | GB, VC30 Bedfordshire, Flitwick | Edgar Wolston Bertram Handsley Milne-Redhead John Patrick Micklethwait Brenan | | 21/7/1946 | K |
| Glechoma hederacea | GB, VC33 East Gloucestershire, Coln Saint Aldwyn | John Patrick Micklethwait Brenan Ronald Burn | John Patrick Micklethwait Brenan | 6/5/1941 | K |
| Glechoma hederacea | GB, VC33 East Gloucestershire, Coln Saint Aldwyn | John Patrick Micklethwait Brenan Ronald Burn | John Patrick Micklethwait Brenan | 6/5/1941 | K |
| Mentha arvensis x aquatica x spicata = M. x smithiana | GB, VC33 East Gloucestershire, Compton Abdale | John Patrick Micklethwait Brenan | | 10/4/1936 | K |
| Festuca pratensis x Lolium perenne = x Festulolium loliaceum | GB, VC34 West Gloucestershire, Bristol | John Norton Mills John Patrick Micklethwait Brenan | | 30/6/1941 | MANCH |
| Verbascum thapsus | GB, VC34 West Gloucestershire, Wotton Hill | John Patrick Micklethwait Brenan | | 22/8/1956 | K |
| Verbascum thapsus | GB, VC34 West Gloucestershire, Wotton-under-Edge | John Patrick Micklethwait Brenan | | 22/8/1956 | K |
| Glebionis segetum | GB, VC35 Monmouthshire, Chepstow | John Patrick Micklethwait Brenan | | 11/9/1935 | K |
| Dactylis glomerata | GB, VC35 Monmouthshire, Wern Fawr | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 9/6/1942 | K |
| Lamium purpureum var. hybridum | GB, VC41 Glamorganshire | John Patrick Micklethwait Brenan | | | K |