Species Recorded | Taxon | Scientific Name | Common Name | Records | Latest |
| algae or stonewort | Fucus serratus | Toothed Wrack | 24 | 2018 |
| algae or stonewort | Fucus spiralis | Spiral Wrack | 23 | 2016 |
| algae or stonewort | Fucus vesiculosus | Bladder Wrack | 46 | 2018 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Fenella nigrita | a sawfly | 1 | 2015 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Fenusa dohrnii | a sawfly | 6 | 2016 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Fenusa (Kaliofenusa) ulmi | a sawfly | 2 | 2018 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Fenusella glaucopis | a sawfly | 1 | 2019 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Formica | a Formica species (unidentified) | 1 | 2011 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Formica fusca | Negro Ant | 44 | 2015 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Formica lemani | an ant | 2 | 1978 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Formica rufa | Red Wood Ant | 32 | 2018 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Formica sanguinea | Slave-making Ant | 1 | 1938 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Formicidae | an ant (unidentified) | 131 | 2018 |
| bird | Falco | a falcon (unidentified) | 7 | 2019 |
| bird | Falco columbarius | Merlin | 974 | 2019 |
| bird | Falco peregrinus | Peregrine | 4480 | 2021 |
| bird | Falco rusticolus | Gyr Falcon | 2 | 2018 |
| bird | Falco subbuteo | Hobby | 4726 | 2019 |
| bird | Falco tinnunculus | Kestrel | 9829 | 2021 |
| bird | Falco vespertinus | Red-footed Falcon | 1 | 1992 |
| bird | Ficedula hypoleuca | Pied Flycatcher | 203 | 2019 |
| bird | Fratercula arctica | Puffin | 1 | 2002 |
| bird | Fregetta sp. | White-bellied or Black-bellied Storm-petrel (unidentified) | 1 | 2009 |
| bird | Fringilla | a Fringilla species (unidentified) | 1 | 2000 |
| bird | Fringilla coelebs | Chaffinch | 25771 | 2021 |
| bird | Fringilla montifringilla | Brambling | 1046 | 2019 |
| bird | Fringillidae | a finch (unidentified) | 19 | 2019 |
| bird | Fulica atra | Coot | 4869 | 2021 |
| bird | Fulmarus glacialis | Fulmar | 91 | 2019 |
| bryozoan | Farrella repens | a bryozoan | 1 | 1976 |
| bug | Fagocyba cruenta | a leafhopper | 3 | 2008 |
| bug | Forda formicaria | an aphid | 1 | 1982 |
| diatom | Fragilaria | a Fragilaria species (unidentified) | 1 | 2015 |
| earwig | Forficula | a Forficula species (unidentified) | 2 | 2014 |
| earwig | Forficula auricularia | Common Earwig | 424 | 2019 |
| earwig | Forficula lesnei | Lesne's earwig | 25 | 2017 |
| fungus | Fistulina hepatica | Beef-steak Fungus | 63 | 2014 |
| fungus | Flagelloscypha minutissima | a basidiomycete fungus | 1 | 2010 |
| fungus | Flammulaster erinaceellus | an agaric | 1 | 1999 |
| fungus | Flammulaster granulosus | an agaric | 6 | 2013 |
| fungus | Flammulaster muricatus | an agaric | 9 | 2014 |
| fungus | Flammulina velutipes | Velvet Shank | 36 | 2019 |
| fungus | Flammulina velutipes var. velutipes | a Velvet Shank | 120 | 2010 |
| fungus | Fomes fomentarius | Hoof Fungus | 3 | 2018 |
| fungus | Fungi | a Fungi species (unidentified) | 2 | 2016 |
| fungus | Fuscoporia ferrea | a basidiomycete fungus | 16 | 2017 |
| fungus | Fuscoporia ferruginosa | a basidiomycete fungus | 35 | 2014 |
| lichen | Flavoparmelia caperata | a lichen | 44 | 2018 |
| lichen | Flavoplaca arcis | a lichen | 1 | 2011 |
| lichen | Flavoplaca citrina | a lichen | 41 | 2018 |
| lichen | Flavoplaca dichroa | a lichen | 9 | 2018 |
| lichen | Flavoplaca flavocitrina | a lichen | 13 | 2018 |
| lichen | Flavoplaca granulosa | a lichen | 1 | 1991 |
| lichen | Flavoplaca marina | a lichen | 2 | 2010 |
| lichen | Flavoplaca oasis | a lichen | 3 | 2014 |
| lichen | Flavoplaca polycarpa | a lichen | 6 | 2018 |
| lichen | Fuscidea | a Fuscidea species (unidentified) | 2 | 2004 |
| lichen | Fuscidea lightfootii | a lichen | 8 | 2011 |
| liverwort | Fossombronia pusilla | Common Frillwort | 3 | 2018 |
| liverwort | Frullania dilatata | Dilated Scalewort | 75 | 2019 |
| liverwort | Frullania tamarisci | Tamarisk Scalewort | 12 | 2019 |
| moss | Fissidens adianthoides | Maidenhair Pocket-moss | 14 | 2012 |
| moss | Fissidens bryoides | Lesser Pocket-moss | 18 | 2019 |
| moss | Fissidens bryoides var. bryoides | a pocket-moss | 1 | 2015 |
| moss | Fissidens crassipes | Fatfoot Pocket-moss | 1 | 1998 |
| moss | Fissidens dubius | Rock Pocket-moss | 27 | 2019 |
| moss | Fissidens exilis | Slender Pocket-moss | 5 | 2010 |
| moss | Fissidens gracilifolius | Narrow-leaved Pocket-moss | 2 | 1963 |
| moss | Fissidens incurvus | Short-leaved Pocket-moss | 10 | 2018 |
| moss | Fissidens pusillus | Petty Pocket-moss | 3 | 2016 |
| moss | Fissidens taxifolius | Common Pocket-moss | 116 | 2019 |
| moss | Fissidens taxifolius var. taxifolius | a common pocket-moss | 2 | 2007 |
| moss | Fissidens viridulus | Green Pocket-moss | 12 | 2019 |
| moss | Fontinalis antipyretica | Greater Water-moss | 14 | 2019 |
| moss | Fontinalis antipyretica var. antipyretica | a greater water-moss | 1 | 1998 |
| moss | Funaria hygrometrica | Common Cord-moss | 15 | 2019 |
| moss | Funaria muhlenbergii | Muhlenberg's Cord-moss | 1 | 1991 |
| moth or butterfly - butterfly | Favonius quercus | Purple Hairstreak | 581 | 2018 |
| moth or butterfly - macro moth | Falcaria lacertinaria | Scalloped Hook-tip | 10 | 2019 |
| moth or butterfly - macro moth | Furcula bicuspis | Alder Kitten | 1 | 1898 |
| moth or butterfly - macro moth | Furcula bifida | Poplar Kitten | 67 | 2018 |
| moth or butterfly - macro moth | Furcula furcula | Sallow Kitten | 247 | 2020 |
| moth or butterfly - micro moth | Falseuncaria degreyana | a micro-moth | 1 | 1906 |
| moth or butterfly - micro moth | Falseuncaria ruficiliana | a micro-moth | 1 | 2007 |
| plant | Fagopyrum esculentum | Buckwheat | 21 | 2014 |
| plant | Fagopyrum tataricum | Green Buckwheat | 3 | 1936 |
| plant | Fagus | a Fagus species (unidentified) | 59 | 2018 |
| plant | Fagus sylvatica | Beech | 3182 | 2020 |
| plant | Fagus sylvatica | Cut-leaved Beech | 2 | 2013 |
| plant | Fagus sylvatica 'Asplenifolia' | Fern-leaved Beech | 3 | 2015 |
| plant | Fagus sylvatica 'Dawyck' | Dawyck Beech | 7 | 2015 |
| plant | Fagus sylvatica Heterophylla group | a beech | 1 | 2016 |
| plant | Fagus sylvatica 'Pendula' | Pendulous Beech | 10 | 2015 |
| plant | Fagus sylvatica 'Purpurea' | Copper Beech | 56 | 2019 |
| plant | Fallopia baldschuanica | Russian Vine | 101 | 2019 |
| plant | Fallopia convolvulus | Black Bindweed | 534 | 2017 |
| plant | Fallopia convolvulus var. convolvulus | a black bindweed | 1 | 2005 |
| plant | Fallopia japonica | Japanese Knotweed | 1253 | 2019 |
| plant | Fallopia japonica x sachalinensis = F. x bohemica | a flowering plant | 1 | 2008 |
| plant | Fallopia japonica x sachalinensis = F. x bohemica | a japanese knotweed | 15 | 2009 |
| plant | Fallopia sachalinensis | Giant Knotweed | 36 | 2017 |
| plant | Fatsia japonica | a sumach | 4 | 2019 |
| plant | Festuca | a fescue (unidentified) | 60 | 2020 |
| plant | Festuca altissima | Wood Fescue | 3 | 2007 |
| plant | Festuca arundinacea | Tall Fescue | 1570 | 2020 |
| plant | Festuca arundinacea x Lolium perenne = X Festulolium holmbergii | a grass | 4 | 1984 |
| plant | Festuca filiformis | Fine-leaved Sheep's-fescue | 2 | 1990 |
| plant | Festuca gigantea | Giant Fescue | 948 | 2019 |
| plant | Festuca lemanii | Confused Fescue | 1 | 1986 |
| plant | Festuca longifolia | Blue Fescue | 3 | 2006 |
| plant | Festuca ovina | Sheep's Fescue | 234 | 2019 |
| plant | Festuca ovina agg. | Sheep's Fescue agg. | 579 | 2016 |
| plant | Festuca ovina subsp. ovina | Sheep's Fescue ssp. ovina | 15 | 2005 |
| plant | Festuca pratensis | Meadow Fescue | 965 | 2019 |
| plant | Festuca pratensis x Lolium multiflorum = X Festulolium braunii | a grass | 2 | 2006 |
| plant | Festuca pratensis x Lolium perenne = X Festulolium loliaceum | a hybrid fescue | 44 | 2019 |
| plant | Festuca rubra | Red Fescue | 3551 | 2020 |
| plant | Festuca rubra agg. | Red Fescue agg. | 987 | 2020 |
| plant | Festuca rubra subsp. commutata | Chewing's Fescue | 9 | 2013 |
| plant | Festuca rubra subsp. juncea | a red fescue | 3 | 2006 |
| plant | Festuca rubra subsp. litoralis | a red fescue | 3 | 2005 |
| plant | Festuca rubra subsp. rubra | a red fescue | 30 | 2005 |
| plant | Ficus carica | Fig | 76 | 2017 |
| plant | Filago arvensis | a cudweed | 2 | 1932 |
| plant | Filago minima | Small Cudweed | 11 | 2015 |
| plant | Filago vulgaris | Common Cudweed | 9 | 2016 |
| plant | Filicopsida | a fern (unidentified) | 77 | 2018 |
| plant | Filipendula purpurea | a meadowsweet | 1 | 1998 |
| plant | Filipendula ulmaria | Meadowsweet | 3740 | 2020 |
| plant | Filipendula vulgaris | Dropwort | 237 | 2019 |
| plant | Flaveria bidentis | Speedy-weed | 1 | 1959 |
| plant | Foeniculum | a Foeniculum species (unidentified) | 1 | 1940 |
| plant | Foeniculum vulgare | Fennel | 327 | 2019 |
| plant | Forsythia | a forsythia (unidentified) | 6 | 2016 |
| plant | Forsythia suspensa | a forsythia | 4 | 2012 |
| plant | Forsythia suspensa x viridissima = F. x intermedia | Border Forsythia | 126 | 2019 |
| plant | Fragaria | a Fragaria species (unidentified) | 3 | 2013 |
| plant | Fragaria ananassa | a flowering plant | 12 | 2013 |
| plant | Fragaria moschata | Hautbois Strawberry | 1 | 1988 |
| plant | Fragaria/Potentilla sp. (unidentified strawberry) | a strawberry (unidentified) | 3 | 2010 |
| plant | Fragaria vesca | Wild Strawberry | 1548 | 2019 |
| plant | Fragaria x ananassa | Garden Strawberry | 27 | 2018 |
| plant | Frangula alnus | Alder Buckthorn | 37 | 2019 |
| plant | Frankenia pulverulenta | European Seaheath | 2 | 1931 |
| plant | Fraxinus | a Fraxinus species (unidentified) | 8 | 2016 |
| plant | Fraxinus americana | White Ash | 7 | 2016 |
| plant | Fraxinus angustifolia | Narrow-leaved Ash | 37 | 2019 |
| plant | Fraxinus angustifolia subsp. oxycarpa | Caucasian Ash | 1 | 2009 |
| plant | Fraxinus excelsior | Ash | 12893 | 2021 |
| plant | Fraxinus excelsior 'Diversifolia' | One-leaved Ash | 10 | 2015 |
| plant | Fraxinus excelsior pendula | Weeping Ash | 1 | 2015 |
| plant | Fraxinus ornus | Manna Ash | 11 | 2020 |
| plant | Fritillaria | a Fritillaria species (unidentified) | 1 | 2014 |
| plant | Fritillaria meleagris | Fritillary (plant) | 25 | 2019 |
| plant | Fuchsia magellanica | Fuchsia | 15 | 2019 |
| plant | Fuchsia sp. | a fuchsia (unidentified) | 1 | 2015 |
| plant | Fumaria | a Fumaria species (unidentified) | 3 | 2018 |
| plant | Fumaria bastardii | Tall Ramping-fumitory | 5 | 2017 |
| plant | Fumaria capreolata | White Ramping-fumitory | 11 | 2016 |
| plant | Fumaria capreolata subsp. babingtonii | a white ramping-fumitory | 4 | 2013 |
| plant | Fumaria densiflora | Dense-flowered Fumitory | 6 | 1992 |
| plant | Fumaria muralis | Common Ramping-fumitory | 4 | 2016 |
| plant | Fumaria muralis subsp. boraei | a Few-flowered Fumitory | 15 | 2016 |
| plant | Fumaria officinalis | Common Fumitory | 340 | 2019 |
| plant | Fumaria officinalis officinalis officinalis | a flowering plant | 1 | 2000 |
| plant | Fumaria officinalis subsp. officinalis | a common fumitory | 9 | 2017 |
| plant | Fumaria officinalis subsp. wirtgenii | a common fumitory | 8 | 2016 |
| slime mould | Fuligo muscorum | a slime mould | 1 | 2008 |
| slime mould | Fuligo septica | a slime mould | 11 | 2016 |
| slime mould | Fuligo septica var. flava | a slime mould | 4 | 1997 |
| slime mould | Fuligo septica var. septica | Dog's Vomit Slime Mould | 15 | 2013 |
| springtail | Folsomia candida | a springtail (Collembola) | 1 | 1963 |
| true fly - | Fannia armata | a lesser house fly | 8 | 2006 |
| true fly - | Fannia canicularis | a lesser house fly | 12 | 2009 |
| true fly - | Fannia coracina | a lesser house fly | 1 | 2009 |
| true fly - | Fannia corvina | a lesser house fly | 1 | 2013 |
| true fly - | Fannia fuscula | a lesser house fly | 2 | 2009 |
| true fly - | Fannia genualis | a lesser house fly | 2 | 2009 |
| true fly - | Fannia lepida | a lesser house fly | 1 | 2001 |
| true fly - | Fannia lustrator | a lesser house fly | 1 | 2001 |
| true fly - | Fannia manicata | a lesser house fly | 1 | 1995 |
| true fly - | Fannia metallipennis | a lesser house fly | 1 | 1948 |
| true fly - | Fannia nidica | a lesser house fly | 1 | 2000 |
| true fly - | Fannia norvegica | a lesser house fly | 3 | 2004 |
| true fly - | Fannia pallitibia | a lesser house fly | 5 | 2008 |
| true fly - | Fannia parva | a lesser house fly | 2 | 2000 |
| true fly - | Fannia polychaeta | a lesser house fly | 2 | 2006 |
| true fly - | Fannia postica | a lesser house fly | 1 | 2002 |
| true fly - | Fannia pseudonorvegica | a lesser house fly | 1 | 1954 |
| true fly - | Fannia rondanii | a lesser house fly | 1 | 2006 |
| true fly - | Fannia scalaris | a lesser house fly | 1 | 1996 |
| true fly - | Fannia serena | a lesser house fly | 22 | 2013 |
| true fly - | Fannia similis | a lesser house fly | 6 | 2006 |
| true fly - | Fannia sociella | a lesser house fly | 1 | 2006 |
| true fly - | Fannia subpubescens | a lesser house fly | 1 | 1996 |
| true fly - | Fannia subsimilis | a lesser house fly | 1 | 2001 |
| true fly - | Fanniidae | a Fanniidae species (unidentified) | 2 | 2015 |
| true fly - | Fucellia maritima (nomen nudum) | a fly | 3 | 1997 |
| true fly - hoverfly | Ferdinandea cuprea | a hoverfly | 31 | 2019 |
| worm | Ficopomatus enigmaticus | Trumpet tube worm | 2 | 1975 |
| worm | Filograna implexa | an annelid | 1 | 1995 |