Species Recorded | Taxon | Scientific Name | Common Name | Records | Latest |
| algae or stonewort | Fucus guiryi | an alga | 1 | 2025 |
| algae or stonewort | Fucus serratus | Toothed Wrack | 26 | 2025 |
| algae or stonewort | Fucus spiralis | Spiral Wrack | 26 | 2025 |
| algae or stonewort | Fucus vesiculosus | Bladder Wrack | 50 | 2025 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Fenella nigrita | Cinquefoil Mining Sawfly | 2 | 2021 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Fenusa dohrnii | Dorhns Alder Mining Sawfly | 6 | 2016 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Fenusa pumila | Small Birch Mining Sawfly | 1 | 2020 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Fenusa ulmi | Elm Mining Sawfly | 3 | 2018 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Fenusella glaucopis | Poplar Mining Sawfly | 1 | 2019 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Formica | Wood Ant | 1 | 2011 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Formica cunicularia | an ant | 1 | 2023 |
| 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 | 37 | 2024 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Formica sanguinea | Slave-making Ant | 1 | 1938 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Formicidae | Invertebrates (Ants) | 169 | 2023 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Formicinae | a Formicinae species (unidentified) | 2 | 2023 |
| bird | Falco | a falcon (unidentified) | 7 | 2019 |
| bird | Falco columbarius | Merlin | 2111 | 2022 |
| bird | Falco peregrinus | Peregrine | 13576 | 2025 |
| bird | Falco rusticolus | Gyr Falcon | 2 | 2018 |
| bird | Falco subbuteo | Hobby | 8121 | 2024 |
| bird | Falco tinnunculus | Kestrel | 29077 | 2025 |
| bird | Falco vespertinus | Red-footed Falcon | 2 | 2014 |
| bird | Ficedula hypoleuca | Pied Flycatcher | 427 | 2024 |
| bird | Fratercula arctica | Puffin | 4 | 2020 |
| 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 | 42704 | 2025 |
| bird | Fringilla montifringilla | Brambling | 2094 | 2022 |
| bird | Fringillidae | Finches | 40 | 2019 |
| bird | Fulica atra | Coot | 13978 | 2025 |
| bird | Fulmarus glacialis | Fulmar | 307 | 2022 |
| 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/dentata agg. | Common Earwig | 547 | 2024 |
| earwig | Forficula lesnei | Lesne's earwig | 25 | 2017 |
| fungus | Fistulina hepatica | Beef-steak Fungus | 67 | 2022 |
| fungus | Flagelloscypha minutissima | Whipped Cuplet | 1 | 2010 |
| fungus | Flammulaster erinaceellus | an agaric | 1 | 1999 |
| fungus | Flammulaster granulosus | Granulose Spark | 6 | 2013 |
| fungus | Flammulaster muricatus | Scaly Spark | 10 | 2022 |
| fungus | Flammulina velutipes | Velvet Shank | 47 | 2023 |
| fungus | Flammulina velutipes var. velutipes | Velvet Shank | 125 | 2025 |
| fungus | Fomes fomentarius | Hoof Fungus | 4 | 2025 |
| fungus | Fomitopsis betulina | Birch Polypore | 126 | 2022 |
| fungus | Fungi | a Fungi species (unidentified) | 51 | 2023 |
| fungus | Fungus (unidentified) | Fungus (unidentified) | 2 | 1977 |
| fungus | Fusarium heterosporum | a fungus | 1 | 2021 |
| fungus | Fuscoporia ferrea | Iron Porecrust | 16 | 2017 |
| fungus | Fuscoporia ferruginosa | Rusty Porecrust | 36 | 2022 |
| lichen | Flavoparmelia caperata | a lichen | 47 | 2023 |
| lichen | Flavoplaca arcis | a lichen | 1 | 2011 |
| lichen | Flavoplaca austrocitrina | a lichen | 3 | 2014 |
| lichen | Flavoplaca citrina s. lat. | a lichen | 42 | 2020 |
| lichen | Flavoplaca dichroa | a lichen | 9 | 2018 |
| lichen | Flavoplaca flavocitrina | a lichen | 13 | 2018 |
| lichen | Flavoplaca granulosa | a lichen | 1 | 1991 |
| lichen | Flavoplaca itiana | a lichen | 10 | 2010 |
| lichen | Flavoplaca limonia | a lichen | 6 | 2011 |
| lichen | Flavoplaca marina | Orange Sea Lichen | 2 | 2010 |
| lichen | Flavoplaca polycarpa | a lichen | 9 | 2018 |
| lichen | Fuscidea | a Fuscidea species (unidentified) | 2 | 2004 |
| lichen | Fuscidea lightfootii | a lichen | 9 | 2025 |
| liverwort | Fossombronia pusilla | Common Frillwort | 3 | 2018 |
| liverwort | Frullania dilatata | Dilated Scalewort | 162 | 2023 |
| liverwort | Frullania tamarisci | Tamarisk Scalewort | 15 | 2023 |
| moss | Fissidens | a Fissidens species (unidentified) | 3 | 2023 |
| moss | Fissidens adianthoides | Maidenhair Pocket-moss | 18 | 2023 |
| moss | Fissidens bryoides | Lesser Pocket-moss | 54 | 2023 |
| moss | Fissidens bryoides var. bryoides | a pocket-moss | 1 | 2015 |
| moss | Fissidens crassipes | Fatfoot Pocket-moss | 1 | 1998 |
| moss | Fissidens curvatus | Portuguese Pocket-moss | 2 | 2023 |
| moss | Fissidens dubius | Rock Pocket-moss | 31 | 2023 |
| moss | Fissidens exilis | Slender Pocket-moss | 5 | 2010 |
| moss | Fissidens gracilifolius | Narrow-leaved Pocket-moss | 3 | 2023 |
| moss | Fissidens incurvus | Short-leaved Pocket-moss | 22 | 2023 |
| moss | Fissidens pusillus | Petty Pocket-moss | 3 | 2016 |
| moss | Fissidens taxifolius | Common Pocket-moss | 174 | 2023 |
| moss | Fissidens viridulus | Green Pocket-moss | 20 | 2023 |
| moss | Flexitrichum flexicaule | Bendy Ditrichum | 9 | 2005 |
| moss | Flexitrichum gracile | Slender Ditrichum | 11 | 2023 |
| moss | Fontinalis antipyretica | Greater Water-moss | 19 | 2022 |
| moss | Fontinalis antipyretica subsp. antipyretica | a greater water-moss | 1 | 1998 |
| moss | Funaria hygrometrica | Common Cord-moss | 40 | 2023 |
| moth or butterfly - butterfly | Fabriciana adippe | High Brown Fritillary | 17 | 1992 |
| moth or butterfly - butterfly | Favonius quercus | Purple Hairstreak | 692 | 2024 |
| moth or butterfly - macro moth | Falcaria lacertinaria | Scalloped Hook-tip | 12 | 2021 |
| moth or butterfly - macro moth | Furcula bicuspis | Alder Kitten | 3 | 2022 |
| moth or butterfly - macro moth | Furcula bifida | Poplar Kitten | 84 | 2024 |
| moth or butterfly - macro moth | Furcula furcula | Sallow Kitten | 309 | 2024 |
| moth or butterfly - micro moth | Falseuncaria degreyana | Breckland Straw | 1 | 1906 |
| moth or butterfly - micro moth | Falseuncaria ruficiliana | Rusty-tipped Straw | 2 | 2020 |
| moth or butterfly - micro moth | Fomoria septembrella | Hypericum Dot | 24 | 2023 |
| plant | Fabaceae | Bean | 6 | 2023 |
| plant | Fagopyrum esculentum | Buckwheat | 23 | 2023 |
| plant | Fagopyrum tataricum | Green Buckwheat | 3 | 1936 |
| plant | Fagus | a Fagus species (unidentified) | 63 | 2023 |
| plant | Fagus sylvatica | Beech | 3597 | 2024 |
| plant | Fagus sylvatica 'Aspleniifolia' | Fern-leaved Beech | 3 | 2015 |
| plant | Fagus sylvatica 'Dawyck' | Dawyck Beech | 7 | 2015 |
| plant | Fagus sylvatica group 'Atropurpurea' | Copper Beech | 62 | 2021 |
| plant | Fagus sylvatica group 'Heterophylla' | Cut-Leaved Beech | 1 | 2016 |
| plant | Fagus sylvatica 'Pendula' | Pendulous Beech | 10 | 2015 |
| plant | Fallopia | a Fallopia species (unidentified) | 3 | 2023 |
| plant | Fallopia baldschuanica | Russian Vine | 109 | 2025 |
| plant | Fallopia convolvulus | Black Bindweed | 547 | 2024 |
| plant | Fallopia convolvulus var. convolvulus | a black bindweed | 1 | 2005 |
| plant | Fatsia | a Fatsia species (unidentified) | 1 | 2022 |
| plant | Fatsia japonica | a sumach | 4 | 2019 |
| plant | Festuca | Fescue | 64 | 2022 |
| plant | Festuca filiformis | Fine-leaved Sheep's-fescue | 2 | 1990 |
| plant | Festuca lemanii | Confused Fescue | 1 | 1986 |
| plant | Festuca longifolia | Blue Fescue | 3 | 2006 |
| plant | Festuca ovina | Sheep's Fescue | 253 | 2024 |
| plant | Festuca ovina agg. | Sheep's Fescue agg. | 579 | 2016 |
| plant | Festuca ovina subsp. ovina | Sheep's Fescue ssp. ovina | 15 | 2005 |
| plant | Festuca rubra | Red Fescue | 3681 | 2024 |
| plant | Festuca rubra agg. | Red Fescue agg. | 988 | 2021 |
| 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 | Ficaria verna | Lesser Celandine | 4879 | 2025 |
| plant | Ficaria verna subsp. fertilis | a lesser celandine | 72 | 2020 |
| plant | Ficaria verna subsp. verna | a lesser celandine | 18 | 2008 |
| plant | Ficus carica | Fig | 79 | 2023 |
| plant | Filago arvensis | Field Cudweed | 2 | 1932 |
| plant | Filago germanica | Common Cudweed | 9 | 2016 |
| plant | Filipendula camtschatica x sp. = F. x purpurea | Filipendula camtschatica x sp. (F. x purpurea) | 1 | 1998 |
| plant | Filipendula ulmaria | Meadowsweet | 3996 | 2024 |
| plant | Filipendula vulgaris | Dropwort | 247 | 2024 |
| plant | Flaveria bidentis | Speedy-weed | 1 | 1959 |
| plant | Foeniculum | a Foeniculum species (unidentified) | 1 | 1940 |
| plant | Foeniculum vulgare | Fennel | 414 | 2024 |
| plant | Forsythia | a forsythia (unidentified) | 7 | 2023 |
| plant | Forsythia suspensa | Golden-bell | 4 | 2012 |
| plant | Forsythia suspensa x viridissima = F. x intermedia | Border Forsythia | 127 | 2019 |
| plant | Fragaria | Strawberry | 8 | 2023 |
| plant | Fragaria ananassa | Garden Strawberry | 41 | 2023 |
| plant | Fragaria moschata | Hautbois Strawberry | 1 | 1988 |
| plant | Fragaria/Potentilla sp. (unidentified strawberry) | a strawberry (unidentified) | 4 | 2018 |
| plant | Fragaria vesca | Wild Strawberry | 1759 | 2024 |
| plant | Frangula alnus | Alder Buckthorn | 39 | 2021 |
| plant | Frankenia pulverulenta | European Seaheath | 3 | 1931 |
| plant | Fraxinus | a Fraxinus species (unidentified) | 10 | 2023 |
| plant | Fraxinus americana | White Ash | 8 | 2024 |
| plant | Fraxinus angustifolia | Narrow-leaved Ash | 38 | 2019 |
| plant | Fraxinus angustifolia subsp. oxycarpa | Caucasian Ash | 1 | 2009 |
| plant | Fraxinus excelsior | Ash | 13544 | 2024 |
| plant | Fraxinus excelsior f. diversifolia | One-leaved Ash | 10 | 2015 |
| plant | Fraxinus excelsior pendula | Weeping Ash | 2 | 2023 |
| plant | Fraxinus ornus | Manna Ash | 11 | 2020 |
| plant | Fritillaria | a Fritillaria species (unidentified) | 1 | 2014 |
| plant | Fritillaria meleagris | Fritillary (plant) | 29 | 2023 |
| plant | Fuchsia magellanica | Fuchsia | 15 | 2019 |
| plant | Fuchsia sp. | a fuchsia (unidentified) | 1 | 2015 |
| plant | Fumaria | Fumitory | 4 | 2023 |
| plant | Fumaria bastardii | Tall Ramping-fumitory | 6 | 2017 |
| plant | Fumaria capreolata | White Ramping-fumitory | 13 | 2020 |
| plant | Fumaria capreolata subsp. babingtonii | Ramping Fumitory | 4 | 2013 |
| plant | Fumaria densiflora | Dense-flowered Fumitory | 7 | 1992 |
| plant | Fumaria muralis | Common Ramping-fumitory | 8 | 2023 |
| plant | Fumaria muralis subsp. boraei | Boreau's Ramping-fumitory | 15 | 2016 |
| plant | Fumaria officinalis | Common Fumitory | 369 | 2024 |
| plant | Fumaria officinalis subsp. officinalis | a common fumitory | 11 | 2022 |
| plant | Fumaria officinalis subsp. officinalis var. officinalis | a flowering plant | 1 | 2000 |
| plant | Fumaria officinalis subsp. wirtgenii | a common fumitory | 9 | 2022 |
| plant | Fumaria reuteri | Martin's Ramping-fumitory | 5 | 2023 |
| slime mould | Fuligo muscorum | a slime mould | 1 | 2008 |
| slime mould | Fuligo septica | a slime mould | 15 | 2022 |
| 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 |
| springtail | Friesea claviseta | a springtail (Collembola) | 2 | 1925 |
| true fly - | Fannia | a Fannia species (unidentified) | 2 | 2023 |
| true fly - | Fannia aequilineata | a lesser house fly | 3 | 2020 |
| true fly - | Fannia armata | a lesser house fly | 9 | 2023 |
| true fly - | Fannia canicularis | a lesser house fly | 13 | 2017 |
| 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 | 2 | 2018 |
| 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 | 3 | 2020 |
| 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 | 23 | 2023 |
| true fly - | Fannia similis | a lesser house fly | 6 | 2006 |
| true fly - | Fannia sociella | a lesser house fly | 3 | 2021 |
| 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 | a fly | 3 | 1997 |
| true fly - hoverfly | Ferdinandea cuprea | a hoverfly | 37 | 2023 |
| worm | Ficopomatus enigmaticus | Trumpet tube worm | 2 | 1975 |
| worm | Filograna implexa | an annelid | 1 | 1995 |