+ | Centaurea cyanus | GB, VC83 Midlothian, Edinburgh,Inverleith | W Horton-Smith | W Horton-Smith | 19/7/1878 | MANCH |
+ | Cerastium alpinum | GB, VC88 Mid Perthshire, Meall nan Tarmachan | J M Webb | W Horton-Smith | 14/8/1878 | MANCH |
+ | Cerastium arcticum | GB, VC97 West Inverness-shire, Ben Nevis | J F Watts | W Horton-Smith | 9/8/1878 | MANCH |
| Ceratocapnos claviculata | GB, VC58 Cheshire, Daresbury | W Horton-Smith | | 26/9/1881 | MANCH |
| Ceratophyllum submersum | GB, VC58 Cheshire, Redesmere | W Horton-Smith | | 18/5/1921 | MANCH |
+ | Chenopodium bonus-henricus | GB, VC28 West Norfolk, Hempton | W Horton-Smith | W Horton-Smith | | MANCH |
+ | Chenopodium bonus-henricus | GB, VC51 Flintshire, Mold, Loggerheads | W Horton-Smith | W Horton-Smith | 3/9/1916 | MANCH |
+ | Chenopodium murale | GB, VC28 West Norfolk, Fakenham,Little Snoring | W Horton-Smith | W Horton-Smith | | MANCH |
+ | Chenopodium urbicum | GB, VC58 Cheshire, Marston | W Horton-Smith | Schill W Horton-Smith | 13/8/1919 | MANCH |
+ | Chrysanthemum segetum | GB, VC28 West Norfolk, Fakenham,Fakenham Heath | | W Horton-Smith | | MANCH |
+ | Chrysanthemum segetum | GB, VC48 Merionethshire, Lake Bala | W Horton-Smith | W Horton-Smith | 27/8/1922 | MANCH |
+ | Chrysanthemum segetum | GB, VC48 Merionethshire, Lake Bala | W Horton-Smith | W Horton-Smith | 27/8/1922 | MANCH |
+ | Chrysanthemum segetum | GB, VC58 Cheshire | W Horton-Smith | | 7/1918 | MANCH |
+ | Chrysanthemum segetum | GB, VC58 Cheshire, Warrington | W Horton-Smith | W Horton-Smith | 3/9/1918 | MANCH |
| Clematis vitalba | GB, VC50 Denbighshire, Bowling Bank | W Horton-Smith | | 26/8/1917 | MANCH |
+ | Cynoglossum officinale | GB, VC28 West Norfolk, Fakenham | W Horton-Smith | W Horton-Smith | | MANCH |
+ | Dactylorhiza majalis subsp. occidentalis | GB, VC28 West Norfolk, Colkirk Wood | W Horton-Smith | | | MANCH |
+ | Dianthus deltoides | GB, VC83 Midlothian, Edinburgh, Queens Park | W Horton-Smith | W Horton-Smith | 16/7/1878 | MANCH |
+ | Drosera anglica | | | W Horton-Smith | | MANCH |
+ | Drosera anglica | GB, VC28 West Norfolk, Fakenham,Fakenham Heath | W Horton-Smith | W Horton-Smith | | MANCH |
+ | Dryopteris cristata | Wood at Bevelaw Edinburgh | W Horton-Smith | | 29/6/1878 | MANCH |
+ | Dryopteris cristata | GB, VC58 Cheshire, Whitley | W Horton-Smith | | 4/8/1877 | MANCH |
+ | Eriocaulon aquaticum | GB, VC104 North Ebudes, Sligachan | John Hutton Balfour | Botanical Society of Edinburgh W Horton-Smith | 8/1841 | MANCH |
| Eriophorum angustifolium | GB, VC28 West Norfolk, Sculthorpe | W Horton-Smith | Manchester Museum | | MANCH |
| Eriophorum angustifolium | GB, VC58 Cheshire, Cat & Fiddle | W Horton-Smith | | 17/6/1917 | MANCH |
| Eriophorum angustifolium | GB, VC58 Cheshire, Delamere Forest | W Horton-Smith | | 21/6/1916 | MANCH |
| Eriophorum angustifolium | GB, VC58 Cheshire, Hatchmere | W Horton-Smith | | 5/6/1918 | MANCH |
+ | Euphrasia arctica x nemorosa | GB, VC58 Cheshire, Banks and fields on dry soil. ?Ravebrig. Edinburgh, . ? | W Horton-Smith | W Horton-Smith | 7/9/1918 | MANCH |
+ | Euphrasia nemorosa x micrantha | GB, VC51 Flintshire, Holywell | W Horton-Smith | W Horton-Smith | 6/8/1916 | MANCH |
| Festuca pratensis x Lolium perenne = x Festulolium loliaceum | GB, VC28 West Norfolk, Fakenham | W Horton-Smith | | | MANCH |
+ | Filago vulgaris | GB, VC2 East Cornwall, Torquay,Whatcombe | Giles Owen | W Horton-Smith | 9/6/1919 | MANCH |
+ | Genista anglica | GB, VC28 West Norfolk, Fakenham,Hempton Green | W Horton-Smith | W Horton-Smith | | MANCH |
+ | Gentianella campestris | GB, VC62 North-east Yorkshire, Sandsend | B R Lucas | W Horton-Smith | | MANCH |
+ | Gentianella campestris | GB, VC88 Mid Perthshire, Killin | Frederick Morgan Webb | W Horton-Smith | 8/1878 | MANCH |
| Geum rivale x urbanum = G. x intermedium | GB, VC50 Denbighshire, Llangollen | W Horton-Smith | | 3/6/1917 | MANCH |
| Geum rivale x urbanum = G. x intermedium | GB, VC83 Midlothian, Edinburgh, Colinton Dell | W Horton-Smith | | 7/7/1878 | MANCH |
| Gnaphalium uliginosum | GB, VC28 West Norfolk, Fakenham | | W Horton-Smith | | MANCH |
| Gnaphalium uliginosum | GB, VC58 Cheshire, Winnington | W Horton-Smith | | 13/8/1915 | MANCH |
| Helleborus foetidus | GB, VC58 Cheshire, Hartford Cultivated | W Horton-Smith | | 28/2/1924 | MANCH |
| Helleborus foetidus | GB, VC58 Cheshire, Hartford | W Horton-Smith | | 28/2/1924 | MANCH |