| Spartina maritima x alterniflora = S. x townsendii | GB, VC6 North Somerset, Clevedon | Harold Stuart Thompson | Harold Stuart Thompson | 23/8/1932 | BIRM |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC6 North Somerset, Sand Bay | Fiona M Audus | | 16/6/1967 | ABS |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC9 Dorset, Poole | Harry Joseph Riddelsdell | Botanical Exchange Club of The British Isles | 10/1905 | ABS |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC9 Dorset, Poole Harbour | Harold Stuart Thompson | Harold Stuart Thompson | 9/1910 | BIRM |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC10 Isle of Wight, Newtown | | Douglas Montague Heath | 22/7/1916 | BIRM |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC10 Isle of Wight, Norton Spit | Edward Francis Linton | Botanical Exchange Club of The British Isles Augustin Ley Edward Francis Linton | 15/9/1893 | BIRM |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC10 Isle of Wight, Quarr | Douglas Montague Heath | Douglas Montague Heath | 2/8/1916 | BIRM |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC10 Isle of Wight, Wootton Creek | Douglas Montague Heath | Douglas Montague Heath | 2/8/1916 | BIRM |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC10 Isle of Wight, Yarmouth | Douglas Montague Heath | Douglas Montague Heath | 8/1913 8/1915 | BIRM |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC10 Isle of Wight, Yarmouth | Douglas Montague Heath | Douglas Montague Heath | 18/8/1915 | BIRM |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC11 South Hampshire, Hayling Island | Edward Shearburn Marshall | Botanical Exchange Club of The British Isles Augustin Ley | 13/9/1900 | BIRM |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC11 South Hampshire, Hythe | | George Claridge Druce George Stephen West | 4/1895 | BIRM |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC11 South Hampshire, Hythe | Henry Groves | Botanical Exchange Club of The British Isles William Hunt Painter | 10/1880 | ABS |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC11 South Hampshire, Hythe | Henry Groves | | 9/10/1883 | BSBI |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC11 South Hampshire, Hythe | Henry Groves | Botanical Exchange Club of The British Isles Augustin Ley Henry & James Groves | 1/9/1879 | BIRM |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC11 South Hampshire, Hythe | Henry Groves James Groves | Botanical Exchange Club of The British Isles Augustin Ley Henry & James Groves | 9/10/1883 | BIRM |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC11 South Hampshire, Hythe | John (Joannis) Fraser | William Hunt Painter | 8/1882 | ABS |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC11 South Hampshire, Hythe | William Hunt Painter | William Hunt Painter | 20/8/1882 | ABS |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC11 South Hampshire, Hythe | C Call | Harold Stuart Thompson John Vaughan | 8/1888 | BIRM |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC13 West Sussex, Bosham | Edward Shearburn Marshall | Botanical Exchange Club of The British Isles Augustin Ley | 1/8/1901 | BIRM |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC13 West Sussex, Chichester | Frederick Henry Arnold | William Hunt Painter | 8/1879 | ABS |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC13 West Sussex, Thorney Island | Richard Spiers Standen | Watson Botanical Exchange Club Edward Cleminshaw | 25/8/1906 | BIRM |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC13 West Sussex, Thorney Island | Thomas Hilton | Watson Botanical Exchange Club Harold Stuart Thompson | 8/1901 | BIRM |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC18 South Essex, Rochford | Cheryl Davies | | 27/8/1967 | ABS |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC19 North Essex, Walton on the Naze | James Thomas Powell | William Hunt Painter | | ABS |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC34 West Gloucestershire, Avonmouth | Newman Neild | Harold Stuart Thompson | 7/1933 | BIRM |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC34 West Gloucestershire, New Passage | Harold Stuart Thompson Job Edward Lousley | Harold Stuart Thompson | 20/7/1933 | BIRM |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC41 Glamorganshire, Jersey marine | T R Lovering | | 20/7/1959 | ABS |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC41 Glamorganshire, Oxwich | A P Roach | | 8/7/1959 | ABS |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC44 Carmarthenshire, Burry Port | Barbara A G Williams | | 9/9/1959 | ABS |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC44 Carmarthenshire, Kidwelly | Clive P Rees | | 10/9/1959 | ABS |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC44 Carmarthenshire, Llanelly | R Anthony Jenkins | | 23/8/1961 | ABS |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC45 Pembrokeshire, Cosheston Creek | J H Croft | | 24/6/1959 | ABS |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC46 Cardiganshire, Aberystwyth | R L Griffith | R L Griffith | 14/10/1961 | ABS |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC46 Cardiganshire, Ynyslas Dunes | Gareth M Evans | Gareth M Evans | 29/6/1961 | ABS |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC46 Cardiganshire, Ynyslas Dunes | M P Russell | | 10/10/1960 | ABS |
| Spartina maritima x alterniflora = S. x townsendii | GB, VC54 North Lincolnshire, Cleethorpes | Pamela M Shaw | | 20/8/1959 | ABS |
| Spartina maritima x alterniflora = S. x townsendii | IE, VCH3 West Cork, Timoleague | Robert Albert Phillips | | 8/1940 | GALW |