| Verbascum virgatum | GB, VC3 South Devon, Man Sands | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 28/7/1937 | K |
| Scrophularia scorodonia | GB, VC41 Glamorganshire, Cardiff, Cardiff Docks | Cecil Ivry Sandwith John Patrick Micklethwait Brenan Royston Leslie Smith | John Patrick Micklethwait Brenan | 4/8/1937 | K |
| Melissa officinalis | GB, VC41 Glamorganshire, Roath | Cecil Ivry Sandwith John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 6/8/1937 | K |
| Glebionis segetum | GB, VC16 West Kent, Sevenoaks | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 12/9/1937 | K |
| Monotropa hypopitys | GB, VC23 Oxfordshire, Nettlebed | Herbert Kenneth Airy Shaw J S Hughes John Patrick Micklethwait Brenan | | 24/10/1937 | K |
| Hypochaeris glabra | GB, VC3 South Devon, East Portlemouth | John Patrick Micklethwait Brenan | | 12/6/1938 | K |
| Plantago maritima | GB, VC66 County Durham, Teesdale | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 16/7/1938 | K |
| 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 |
| Rubus lettii | IE, VCH38 Co. Down, Banbridge | John Patrick Micklethwait Brenan Norman Douglas Simpson | Norman Douglas Simpson | 1/8/1938 | SLBI |
| Thymus praecox subsp. arcticus | IE, VCH34,VCH40, Magilligan Point | Norman Douglas Simpson | John Patrick Micklethwait Brenan | 6/8/1938 | K |
| Thymus praecox subsp. arcticus | IE, VCH40 Co. Londonderry, Magilligan point | John Patrick Micklethwait Brenan Norman Douglas Simpson | | 6/8/1938 | K |
| Hypochaeris glabra | IE, VCH40 Co. Londonderry, Magilligan point | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 23/8/1938 | K |
| Satureja montana | GB, VC11 South Hampshire, Beaulieu Abbey | John Patrick Micklethwait Brenan Norman Douglas Simpson Richard Charles L'Estrange Burges | John Patrick Micklethwait Brenan | 5/9/1938 | K |
| Leonurus cardiaca | GB, VC23 Oxfordshire, Oxford | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 21/6/1939 | K |
| Rubus lettii | IE, VCH39 Co. Antrim, Crumlin | John Patrick Micklethwait Brenan Norman Douglas Simpson | Norman Douglas Simpson | 16/8/1939 | SLBI |
| Rubus pruinosus | IE, VCH39 Co. Antrim, Drumnadarragh | John Patrick Micklethwait Brenan Norman Douglas Simpson | | 17/8/1939 | SLBI |
| Rubus pruinosus | IE, VCH39 Co. Antrim, Drumnadarragh | John Patrick Micklethwait Brenan Norman Douglas Simpson | William Charles Richard Watson | 17/8/1939 | SLBI |
| Melissa officinalis | GB, VC16 West Kent, Tonbridge | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 23/8/1939 | K |
| Veronica persica var. kochiana | GB, VC16 West Kent, Halling | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 31/8/1939 | 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 |
| 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 |
| Festuca pratensis x Lolium perenne = x Festulolium loliaceum | GB, VC34 West Gloucestershire, Bristol | John Norton Mills John Patrick Micklethwait Brenan | | 30/6/1941 | MANCH |
+ | Wahlenbergia hederacea | GB, VC3 South Devon, Chagford | John Patrick Micklethwait Brenan | John Norton Mills | 2/8/1941 | MANCH |
| Mentha arvensis x aquatica = M. x verticillata | GB, VC23 Oxfordshire, Oxford,Port Meadow | John Patrick Micklethwait Brenan Noel Yvri Sandwith | | 30/8/1941 | K |
| Dactylis glomerata | GB, VC35 Monmouthshire, Wern Fawr | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 9/6/1942 | K |
| Dactylis glomerata | GB, VC46 Cardiganshire, Cae Melyn | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 19/6/1942 | K |
| Hypochaeris glabra | GB, VC9 Dorset, Sandford | John Patrick Micklethwait Brenan Norman Douglas Simpson | John Patrick Micklethwait Brenan | 28/6/1942 | K |
| Dactylis glomerata | GB, VC6 North Somerset, Shepton Mallet | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 6/9/1942 | K |
| Carex montana | GB, VC6 North Somerset, Velvet Bottom | John Patrick Micklethwait Brenan | John Norton Mills | 23/4/1943 | MANCH |
| Festuca arundinacea | GB, VC23 Oxfordshire, South Leigh | John Patrick Micklethwait Brenan Ronald Burn | John Patrick Micklethwait Brenan | 30/5/1943 | K |
| Rumex crispus | GB, VC22 Berkshire, King's Weir | John Patrick Micklethwait Brenan | John Patrick Micklethwait Brenan | 11/7/1943 | SLBI |
+ | Cynodon dactylon | GB, VC1 West Cornwall, Penzance,Marazion | John Patrick Micklethwait Brenan N E G Cruttwell | John Norton Mills | 5/8/1943 | MANCH |
| Stachys sylvatica x palustris = S. x ambigua | GB, VC1 West Cornwall, Gwinear | John Patrick Micklethwait Brenan N E G Cruttwell | John Patrick Micklethwait Brenan | 9/8/1943 | K |
| Potamogeton polygonifolius | GB, VC6 North Somerset, Shapwick | John Norton Mills John Patrick Micklethwait Brenan | John Norton Mills | 4/7/1944 | MANCH |
+ | Euphrasia anglica | GB, VC6 North Somerset | John Norton Mills John Patrick Micklethwait Brenan | John Norton Mills | 5/7/1944 | MANCH |
| Aconitum napellus | GB, VC6 North Somerset, Stoke Lane | John Norton Mills John Patrick Micklethwait Brenan | John Norton Mills | 5/7/1944 | MANCH |
| Aconitum napellus | GB, VC6 North Somerset, Stoke Lane | John Norton Mills John Patrick Micklethwait Brenan | John Norton Mills | 5/7/1944 | MANCH |
| Phalaris arundinacea | GB, VC6 North Somerset, Cheddar | John Patrick Micklethwait Brenan | | 8/7/1944 | K |