Species Recorded | Taxon | Scientific Name | Common Name | Records | Latest |
| ant, bee, wasp, sawfly or ichneumon (and others) | Gasteruption | a Gasteruption species (unidentified) | 4 | 2016 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Gasteruption assectator | a parasitic wasp | 2 | 2016 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Gasteruption jaculator | a parasitic wasp | 20 | 2020 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Gelis agilis | an insect - hymenopteran | 1 | 2009 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Gelis areator | an insect - hymenopteran | 1 | 2002 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Gelis festinans | an insect - hymenopteran | 1 | 2008 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Glyphicnemis | a Glyphicnemis species (unidentified) | 1 | 2016 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Glypta ceratites | an ichneumon wasp | 2 | 1998 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Glyptapanteles inclusus | a braconid wasp | 1 | 2009 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Glyptapanteles lateralis | a braconid wasp | 1 | 1997 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Glypta trochanterata | an ichneumon wasp | 1 | 2003 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Gorytes laticinctus | a solitary wasp | 2 | 2008 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Gorytes quadrifasciatus | 4-banded Digger Wasp | 6 | 2013 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Gravenhorstia (Erigorgus) cerinops | an ichneumon wasp | 1 | 2006 |
| ant, bee, wasp, sawfly or ichneumon (and others) | Gymnomerus laevipes | a potter wasp or mason wasp | 3 | 2008 |
| beetle | Gabrius appendiculatus | a rove beetle | 1 | 2015 |
| beetle | Gabrius breviventer | a rove beetle | 4 | 2017 |
| beetle | Gabrius splendidulus | a rove beetle | 1 | 2001 |
| beetle | Galeruca tanaceti | a leaf beetle | 1 | 2000 |
| beetle | Galerucella | a Galerucella species (unidentified) | 1 | 1999 |
| beetle | Galerucella calmariensis | a leaf beetle | 9 | 2002 |
| beetle | Galerucella grisescens | a leaf beetle | 2 | 1983 |
| beetle | Galerucella lineola | Brown Willow Beetle | 14 | 2018 |
| beetle | Galerucella pusilla | a leaf beetle | 1 | 1983 |
| beetle | Galerucella sagittariae | a leaf beetle | 5 | 2017 |
| beetle | Galerucella tenella | a leaf beetle | 4 | 2018 |
| beetle | Gastrophysa | a Gastrophysa species (unidentified) | 1 | 2016 |
| beetle | Gastrophysa polygoni | a leaf beetle | 11 | 2015 |
| beetle | Gastrophysa viridula | Green Dock Beetle | 215 | 2020 |
| beetle | Gauropterus fulgidus | a rove beetle | 1 | 2015 |
| beetle | Geotrupes mutator | a dumbledor | 1 | 1965 |
| beetle | Geotrupes spiniger | a dumbledor | 3 | 2008 |
| beetle | Geotrupes stercorarius | Dor Beetle | 4 | 2018 |
| beetle | Glaphyra umbellatarum | a longhorn beetle | 1 | 2018 |
| beetle | Glischrochilus (Librodor) quadriguttatus | a pollen or sap beetle | 2 | 2016 |
| beetle | Glocianus distinctus | a weevil | 2 | 2018 |
| beetle | Gnathoncus nannetensis | a carrion beetle | 2 | 2016 |
| beetle | Gonioctena olivacea | Broom Leaf Beetle | 2 | 2004 |
| beetle | Gonodera luperus | a darkling beetle | 3 | 2013 |
| beetle | Gracilia minuta | a longhorn beetle | 1 | 2019 |
| beetle | Grammoptera | a Grammoptera species (unidentified) | 1 | 2012 |
| beetle | Grammoptera abdominalis | a longhorn beetle | 1 | 1950 |
| beetle | Grammoptera ruficornis | a longhorn beetle | 159 | 2019 |
| beetle | Graptodytes bilineatus | a water beetle | 37 | 2009 |
| beetle | Graptodytes pictus | a water beetle | 86 | 2013 |
| beetle | Graptus triguttatus | a weevil | 9 | 2017 |
| beetle | Grynobius planus | a wood boring beetle | 3 | 2015 |
| beetle | Grypus equiseti | Horsetail Weevil | 6 | 2010 |
| beetle | Gymnetron melanarium | a weevil | 9 | 2010 |
| beetle | Gymnetron villosulum | a weevil | 5 | 2008 |
| beetle | Gyrinidae | a Gyrinidae whirligig beetle (unidentified) | 41 | 2017 |
| beetle | Gyrinus | a Gyrinus whirligig beetle (unidentified) | 47 | 2018 |
| beetle | Gyrinus caspius | a whirligig | 2 | 2004 |
| beetle | Gyrinus marinus | a whirligig | 17 | 2011 |
| beetle | Gyrinus substriatus | a whirligig | 89 | 2018 |
| beetle | Gyrohypnus angustatus | a rove beetle | 1 | 1978 |
| beetle | Gyrohypnus fracticornis | a rove beetle | 9 | 2017 |
| bird | Gallinago gallinago | Snipe | 3591 | 2021 |
| bird | Gallinula chloropus | Moorhen | 7586 | 2021 |
| bird | Garrulus glandarius | Jay | 13712 | 2021 |
| bird | Gavia arctica | Black-throated Diver | 109 | 2019 |
| bird | Gavia immer | Great Northern Diver | 117 | 2019 |
| bird | Gavia pacifica | Pacific Diver | 1 | 2009 |
| bird | Gavia stellata | Red-throated Diver | 76 | 2019 |
| bird | Geopelia cuneata | Diamond Dove | 1 | 2018 |
| bird | Glareola nordmanni | Black-winged Pratincole | 1 | 1968 |
| bird | Goose sp.(a grey goose (unidentified) | a grey goose (unidentified) | 2 | 2004 |
| bird | Grus grus | Crane | 21 | 2019 |
| booklouse or barklouse | Graphopsocus cruciatus | a booklouse or barklouse | 7 | 2012 |
| bug | Gastrodes abietum | a ground bug | 1 | 2013 |
| bug | Gerridae | a pondskater (unidentified) | 105 | 2020 |
| bug | Gerris | a Gerris pondskater (unidentified) | 143 | 2017 |
| bug | Gerris (Gerris) argentatus | Little Pondskater | 1 | 1949 |
| bug | Gerris (Gerris) gibbifer | a pondskater | 8 | 2006 |
| bug | Gerris (Gerris) lacustris | Common Pondskater | 130 | 2019 |
| bug | Gerris (Gerris) odontogaster | Toothed Pondskater | 18 | 2013 |
| bug | Gerris (Gerris) thoracicus | a pondskater | 23 | 2013 |
| bug | Gerris rufoscutellatus | an insect - true bug (Hemiptera) | 1 | 1991 |
| bug | Gerroidea | a Gerroidea species (unidentified) | 1 | 2005 |
| bug | Gonocerus acuteangulatus | Box Bug | 15 | 2020 |
| bug | Graphocephala fennahi | a leafhopper | 1 | 2017 |
| bug | Graptopeltus lynceus | a ground bug | 1 | 2007 |
| bug | Grypocoris (Lophyromiris) stysi | a plantbug or grassbug | 56 | 2020 |
| caddis fly | Glossosomatidae | a Glossosomatidae species (unidentified) | 1 | 1993 |
| caddis fly | Glyphotaelius pellucidus | a caddisfly | 14 | 2020 |
| caddis fly | Goera pilosa | a caddisfly | 1 | 1977 |
| centipede | Geophilidae | a Geophilidae species (unidentified) | 1 | 2012 |
| centipede | Geophilomorpha | a Geophilomorpha species (unidentified) | 1 | 2000 |
| centipede | Geophilus carpophagus | Luminous centipede | 1 | 1978 |
| centipede | Geophilus flavus | a centipede | 3 | 1997 |
| centipede | Geophilus truncorum | Small geophilus | 2 | 1999 |
| crustacean | Galathea squamifera | Black Squat Lobster | 2 | 1989 |
| crustacean | Gammarellus homari | a crustacean | 4 | 1940 |
| crustacean | Gammarus | a freshwater shrimp (unidentified) | 173 | 2018 |
| crustacean | Gammarus chevreuxi | a freshwater shrimp | 1 | 2005 |
| crustacean | Gammarus lacustris | a freshwater shrimp | 3 | 2015 |
| crustacean | Gammarus locusta | a crustacean | 2 | 1939 |
| crustacean | Gammarus pulex | Common Freshwater Shrimp | 120 | 2019 |
| crustacean | Gammarus salinus | a crustacean | 27 | 1973 |
| crustacean | Gammarus zaddachi | a freshwater shrimp | 11 | 2013 |
| crustacean | Gastrosaccus spinifer | a crustacean | 1 | 1939 |
| diatom | Gomphonema | a gomphonema diatom (unidentified) | 1 | 2010 |
| diatom | Gomphonema angustatum | a diatom | 1 | 2015 |
| diatom | Gomphonema angustum | a diatom | 1 | 2015 |
| diatom | Gomphonema olivaceum | a diatom | 1 | 2015 |
| diatom | Gomphonema pumilum | a diatom | 1 | 2015 |
| fish | Gadus morhua | Cod | 12 | 2015 |
| fish | Gaidropsarus vulgaris | Three-bearded Rockling | 2 | 2012 |
| fish | Galeorhinus galeus | Tope | 3 | 2011 |
| fish | Gasterosteidae | a stickleback (unidentified) | 36 | 2017 |
| fish | Gasterosteus aculeatus | Three-spined Stickleback | 264 | 2019 |
| fish | Glyptocephalus cynoglossus | Witch | 2 | 1879 |
| fish | Gobio gobio | Gudgeon | 52 | 2018 |
| fish | Gobiusculus flavescens | Two-spotted Goby | 2 | 1933 |
| fish | Gobius niger | Black Goby | 2 | 2016 |
| fungus | Gabarnaudia | a Gabarnaudia species (unidentified) | 1 | 2017 |
| fungus | Galerina | a Galerina species (unidentified) | 1 | 1998 |
| fungus | Galerina atkinsoniana | an agaric | 4 | 2010 |
| fungus | Galerina clavata | an agaric | 84 | 2014 |
| fungus | Galerina graminea | an agaric | 24 | 2014 |
| fungus | Galerina heterocystis | an agaric | 1 | 2003 |
| fungus | Galerina hypnorum | an agaric | 8 | 2014 |
| fungus | Galerina marginata | an agaric | 94 | 2018 |
| fungus | Galerina pumila | an agaric | 10 | 2012 |
| fungus | Galerina septentrionalis | an agaric | 1 | 2004 |
| fungus | Galerina sideroides | an agaric | 6 | 2014 |
| fungus | Galerina sphagnorum | an agaric | 1 | 1996 |
| fungus | Galerina stylifera | an agaric | 32 | 2014 |
| fungus | Galerina uncialis | an agaric | 1 | 2005 |
| fungus | Galerina vittiformis | an agaric | 129 | 2014 |
| fungus | Ganoderma | a basidiomycete fungus (unidentified) | 14 | 2019 |
| fungus | Ganoderma applanatum | a basidiomycete fungus | 34 | 2019 |
| fungus | Ganoderma australe | a basidiomycete fungus | 87 | 2017 |
| fungus | Ganoderma lucidum | a basidiomycete fungus | 27 | 2010 |
| fungus | Geastrum | a Geastrum (Earthstar) species (unidentified) | 5 | 2017 |
| fungus | Geastrum fimbriatum | Sessile Earthstar | 16 | 2012 |
| fungus | Geastrum fornicatum | Arched Earthstar | 1 | 1994 |
| fungus | Geastrum pectinatum | Beaked Earthstar | 4 | 2014 |
| fungus | Geastrum rufescens | Rosy Earthstar | 5 | 2009 |
| fungus | Geastrum striatum | Striated Earthstar | 6 | 2012 |
| fungus | Geastrum triplex | Collared Earthstar | 122 | 2019 |
| fungus | Geoglossum cookeanum | an ascomycete fungus | 7 | 2010 |
| fungus | Geoglossum fallax | an ascomycete fungus | 2 | 2008 |
| fungus | Geoglossum umbratile | a fungus | 13 | 2020 |
| fungus | Geopora sumneriana | a fungus | 2 | 2018 |
| fungus | Geopyxis carbonaria | a fungus | 1 | 2014 |
| fungus | Gliophorus irrigatus | a basidiomycete fungus | 43 | 2020 |
| fungus | Gliophorus laetus | a basidiomycete fungus | 2 | 2009 |
| fungus | Gliophorus psittacinus | a fungus | 37 | 2015 |
| fungus | Gliophorus psittacinus | Parrot Wax-cap | 145 | 2020 |
| fungus | Gloeocystidiellum porosellum | a fungus | 1 | 1987 |
| fungus | Glomus microcarpum | a fungus | 2 | 2008 |
| fungus | Gloniopsis praelonga | a fungus | 3 | 2010 |
| fungus | Gnomonia cerastis | an ascomycete fungus | 5 | 1998 |
| fungus | Golovinomyces biocellatus | a conidial powdery mildew | 3 | 2008 |
| fungus | Golovinomyces cichoracearum var. cichoracearum | a conidial powdery mildew | 8 | 2013 |
| fungus | Golovinomyces cichoracearum var. cichoracearum | a fungus | 3 | 2014 |
| fungus | Golovinomyces cynoglossi | a conidial powdery mildew | 6 | 2014 |
| fungus | Golovinomyces depressus | a conidial powdery mildew | 3 | 2009 |
| fungus | Golovinomyces fischeri | a conidial powdery mildew | 1 | 1997 |
| fungus | Golovinomyces orontii | a conidial powdery mildew | 2 | 2008 |
| fungus | Golovinomyces sordidus | a conidial powdery mildew | 13 | 2013 |
| fungus | Golovinomyces sordidus | Plantain Mildew | 5 | 2014 |
| fungus | Golovinomyces sparsus | a conidial powdery mildew | 2 | 2008 |
| fungus | Gomphidius glutinosus | a bolete | 1 | 1970 |
| fungus | Gomphidius maculatus | a bolete | 8 | 2014 |
| fungus | Graddonia coracina | an ascomycete fungus | 2 | 2008 |
| fungus | Granulobasidium vellereum | a basidiomycete fungus | 3 | 2010 |
| fungus | Grifola frondosa | a basidiomycete fungus | 7 | 2014 |
| fungus | Grifola frondosa | a fungus | 1 | 1970 |
| fungus | Guepinia helvelloides | a basidiomycete fungus | 1 | 2010 |
| fungus | Guignardia aesculi | a fungus | 5 | 2015 |
| fungus | Gymnopilus bellulus | an agaric | 3 | 2013 |
| fungus | Gymnopilus hybridus | an agaric | 3 | 2003 |
| fungus | Gymnopilus junonius | an agaric | 17 | 2014 |
| fungus | Gymnopilus penetrans | an agaric | 60 | 2014 |
| fungus | Gymnopilus sapineus | an agaric | 1 | 2013 |
| fungus | Gymnopus | a Micromphale species (unidentified) | 4 | 1999 |
| fungus | Gymnopus androsaceus | Horsehair Parachute | 20 | 2008 |
| fungus | Gymnopus aquosus | a fungus | 4 | 2012 |
| fungus | Gymnopus brassicolens | a basidiomycete fungus | 1 | 1993 |
| fungus | Gymnopus brassicolens var. brassicolens | a basidiomycete fungus | 4 | 1999 |
| fungus | Gymnopus confluens | Clustered Tough-shank | 158 | 2014 |
| fungus | Gymnopus dryophilus | Russet Shank | 350 | 2015 |
| fungus | Gymnopus erythropus | a basidiomycete fungus | 8 | 2014 |
| fungus | Gymnopus foetidus | a basidiomycete fungus | 11 | 2002 |
| fungus | Gymnopus fuscopurpureus | a basidiomycete fungus | 1 | 1978 |
| fungus | Gymnopus fusipes | Spindle Shank | 52 | 2017 |
| fungus | Gymnopus impudicus | a basidiomycete fungus | 3 | 2000 |
| fungus | Gymnopus ocior | a basidiomycete fungus | 18 | 2012 |
| fungus | Gymnopus peronatus | Wood Woolly-foot | 88 | 2014 |
| fungus | Gymnopus quercophilus | a fungus | 1 | 2008 |
| fungus | Gymnosporangium clavariiforme | a rust | 3 | 2015 |
| fungus | Gymnosporangium confusum | a rust | 10 | 2018 |
| fungus | Gymnosporangium sabinae | a fungus | 3 | 2015 |
| fungus | Gyrodon lividus | a bolete | 2 | 2014 |
| grasshopper, cricket or true cricket | Gomphocerippus rufus | Rufous Grasshopper | 57 | 2019 |
| grasshopper, cricket or true cricket | Gryllus campestris | Field Cricket | 1 | 2014 |
| hairworm | Gordius | a Gordius species (unidentified) | 1 | 2009 |
| leech, flatworm or ribbon worm | Girardia tigrina | a flatworm | 3 | 2020 |
| leech, flatworm or ribbon worm | Glossiphonia | a Glossiphonia leech (unidentified) | 6 | 2014 |
| leech, flatworm or ribbon worm | Glossiphonia complanata | a leech | 78 | 2019 |
| leech, flatworm or ribbon worm | Glossiphoniidae | a Glossiphonidae leech (unidentified) | 18 | 2003 |
| lichen | Graphina anguina | a lichen | 1 | 1996 |
| lichen | Graphis elegans | a lichen | 3 | 1996 |
| lichen | Graphis scripta | Script Lichen | 18 | 2019 |
| lichen | Gyalecta jenensis var. jenensis | a lichen | 13 | 2018 |
| lichen | Gyalolechia flavovirescens | a lichen | 2 | 2011 |
| millipede | Geoglomeris subterranea | a pill millepede | 1 | 1987 |
| millipede | Glomeris marginata | Pill Millipede | 82 | 2019 |
| mollusc | Galba (Galba) truncatula | a pond snail | 16 | 2013 |
| mollusc | Gastrochaenidae | a Gastrochaenidae species (unidentified) | 1 | 2021 |
| mollusc | Gastropoda | a Gastropoda species (unidentified) | 4 | 2016 |
| mollusc | Gyraulus (Armiger) crista | Nautilus Ramshorn | 16 | 2013 |
| mollusc | Gyraulus (Gyraulus) albus | White Ramshorn | 26 | 2013 |
| moss | Grimmia | a Grimmia species (unidentified) | 1 | 2013 |
| moss | Grimmia donniana | Donn's Grimmia | 1 | 1990 |
| moss | Grimmia orbicularis | Round-fruited Grimmia | 3 | 1998 |
| moss | Grimmia pulvinata | Grey-cushioned Grimmia | 60 | 2019 |
| moss | Gymnostomum calcareum | Blunt-leaf Tufa-moss | 1 | 1963 |
| moss | Gyroweisia tenuis | Slender Stubble-moss | 4 | 2016 |
| moth or butterfly - butterfly | Gonepteryx rhamni | Brimstone (butterfly) | 10161 | 2020 |
| moth or butterfly - macro moth | Gandaritis pyraliata | Barred Straw | 364 | 2020 |
| moth or butterfly - macro moth | Gastropacha quercifolia | Lappet | 19 | 2013 |
| moth or butterfly - macro moth | Geometra papilionaria | Large Emerald | 86 | 2018 |
| moth or butterfly - macro moth | Geometridae | a Geometridae moth (unidentified) | 2 | 1998 |
| moth or butterfly - macro moth | Geometridae | a Geometridae species (unidentified) | 1 | 2009 |
| moth or butterfly - macro moth | Gortyna flavago | Frosted Orange | 270 | 2020 |
| moth or butterfly - macro moth | Graphiphora augur | Double Dart | 28 | 2015 |
| moth or butterfly - macro moth | Griposia aprilina | Merveille du Jour | 151 | 2019 |
| moth or butterfly - macro moth | Gymnoscelis rufifasciata | Double-striped Pug | 2438 | 2020 |
| moth or butterfly - micro moth | Galleria mellonella | Wax Moth | 140 | 2018 |
| moth or butterfly - micro moth | Gelechia rhombella | a micro-moth | 2 | 2007 |
| moth or butterfly - micro moth | Gelechia sororculella | a micro-moth | 3 | 2015 |
| moth or butterfly - micro moth | Gibberifera simplana | a tortrix moth | 1 | 1996 |
| moth or butterfly - micro moth | Gillmeria ochrodactyla | Tansy Plume | 8 | 2014 |
| moth or butterfly - micro moth | Gillmeria pallidactyla | Yarrow Plume | 27 | 2019 |
| moth or butterfly - micro moth | Glyphipterix equitella | a micro-moth | 1 | 1997 |
| moth or butterfly - micro moth | Glyphipterix forsterella | a micro-moth | 19 | 2016 |
| moth or butterfly - micro moth | Glyphipterix fuscoviridella | a micro-moth | 57 | 2020 |
| moth or butterfly - micro moth | Glyphipterix simpliciella | Cocksfoot Moth | 175 | 2020 |
| moth or butterfly - micro moth | Glyphipterix thrasonella | a micro-moth | 36 | 2019 |
| moth or butterfly - micro moth | Gracillaria syringella | Common Slender | 247 | 2019 |
| moth or butterfly - micro moth | Grapholita compositella | a tortrix moth | 34 | 2017 |
| moth or butterfly - micro moth | Grapholita funebrana | Plum Fruit Moth | 18 | 2018 |
| moth or butterfly - micro moth | Grapholita janthinana | a tortrix moth | 35 | 2018 |
| moth or butterfly - micro moth | Grapholita jungiella | a tortrix moth | 50 | 2017 |
| moth or butterfly - micro moth | Grapholita lathyrana | a tortrix moth | 1 | 2012 |
| moth or butterfly - micro moth | Grapholita lobarzewskii | a tortrix moth | 12 | 2018 |
| moth or butterfly - micro moth | Grapholita lunulana | a tortrix moth | 1 | 1993 |
| moth or butterfly - micro moth | Grapholita tenebrosana | a tortrix moth | 1 | 2002 |
| moth or butterfly - micro moth | Gynnidomorpha alismana | a micro-moth | 11 | 2013 |
| moth or butterfly - micro moth | Gynnidomorpha permixtana | a micro-moth | 1 | 1906 |
| moth or butterfly - micro moth | Gynnidomorpha vectisana | a micro-moth | 8 | 2018 |
| moth or butterfly - micro moth | Gypsonoma aceriana | a tortrix moth | 4 | 2018 |
| moth or butterfly - micro moth | Gypsonoma dealbana | Common Cloaked Shoot | 136 | 2020 |
| moth or butterfly - micro moth | Gypsonoma minutana | a tortrix moth | 2 | 2018 |
| moth or butterfly - micro moth | Gypsonoma oppressana | a tortrix moth | 6 | 2017 |
| moth or butterfly - micro moth | Gypsonoma sociana | a tortrix moth | 23 | 2017 |
| peanut worm (sipuncula) | Golfingia (Golfingia) margaritacea | a peanut worm (Sipuncula) | 1 | 1995 |
| plant | Gagea lutea | Yellow Star-of-Bethlehem | 12 | 2017 |
| plant | Galanthus | a Galanthus species (unidentified) | 2 | 2010 |
| plant | Galanthus caucasicus | Caucasian Snowdrop | 2 | 2006 |
| plant | Galanthus elwesii | Greater Snowdrop | 7 | 2017 |
| plant | Galanthus nivalis | Snowdrop | 512 | 2019 |
| plant | Galanthus nivalis x plicatus | a snowdrop | 5 | 2006 |
| plant | Galanthus plicatus | Pleated Snowdrop | 5 | 2016 |
| plant | Galanthus plicatus subsp. byzantinus | a snowdrop | 6 | 2014 |
| plant | Galanthus plicatus subsp. plicatus | a snowdrop | 11 | 2014 |
| plant | Galanthus woronowii | a flowering plant | 4 | 2014 |
| plant | Galega officinalis | Goat's-rue | 10 | 2019 |
| plant | Galeopsis angustifolia | Red Hemp-nettle | 12 | 2008 |
| plant | Galeopsis bifida | Bifid Hemp-nettle | 18 | 2011 |
| plant | Galeopsis ladanum | Broad-leaved Hemp-nettle | 1 | 1931 |
| plant | Galeopsis tetrahit | Common Hemp-nettle | 194 | 2019 |
| plant | Galeopsis tetrahit agg. (sensu lato) | Common Hemp-nettle [agg.] | 14 | 2006 |
| plant | Galinsoga parviflora | Gallant Soldier | 19 | 2015 |
| plant | Galinsoga quadriradiata | Shaggy Soldier | 37 | 2018 |
| plant | Galium | a bedstraw (unidentified) | 28 | 2018 |
| plant | Galium aparine | Cleavers | 7146 | 2020 |
| plant | Galium mollugo | Hedge Bedstraw | 2648 | 2020 |
| plant | Galium mollugo subsp. erectum | Upright Hedge Bedstraw | 210 | 2017 |
| plant | Galium mollugo subsp. mollugo | Great Hedge Bedstraw | 11 | 2011 |
| plant | Galium murale | a flowering plant | 1 | 2019 |
| plant | Galium odoratum | Woodruff | 565 | 2019 |
| plant | Galium palustre | Marsh-bedstraw | 984 | 2019 |
| plant | Galium palustre subsp. elongatum | a common marsh-bedstraw | 17 | 2016 |
| plant | Galium palustre subsp. palustre | a common marsh-bedstraw | 40 | 2016 |
| plant | Galium parisiense | Wall Bedstraw | 3 | 2017 |
| plant | Galium pumilum | a flowering plant | 2 | 1985 |
| plant | Galium pumilum | Slender Bedstraw | 5 | 2003 |
| plant | Galium saxatile | Heath Bedstraw | 175 | 2019 |
| plant | Galium spurium | False Cleavers | 3 | 1959 |
| plant | Galium tricornutum | Corn Cleavers | 2 | 1962 |
| plant | Galium uliginosum | Fen Bedstraw | 98 | 2018 |
| plant | Galium verum | Lady's Bedstraw | 2924 | 2020 |
| plant | Galium verum x mollugo = G. x pomeranicum | Hybrid Yellow Bedstraw | 13 | 2020 |
| plant | Garrya elliptica | a dogwood | 35 | 2000 |
| plant | Gastridium ventricosum | Nit-grass | 20 | 2013 |
| plant | Gaudinia fragilis | French Oat-grass | 49 | 2015 |
| plant | Gaura | a Gaura species (unidentified) | 1 | 2012 |
| plant | Genista anglica | Petty Whin | 4 | 2008 |
| plant | Genista hispanica | Spanish Gorse | 7 | 2000 |
| plant | Genista tinctoria | Dyer's Greenweed | 256 | 2019 |
| plant | Genista tinctoria subsp. tinctoria | a dyer's greenweed | 146 | 2004 |
| plant | Gentiana | a Gentiana species (unidentified) | 4 | 2011 |
| plant | Gentianella amarella | Autumn Gentian | 47 | 2015 |
| plant | Gentianella amarella subsp. amarella | an autumn gentian | 52 | 1999 |
| plant | Gentianella anglica | Early Gentian | 1 | 1955 |
| plant | Geraniaceae | a Geraniaceae species (unidentified) | 1 | 2010 |
| plant | Geranium | a geranium (unidentified) | 65 | 2020 |
| plant | Geranium columbinum | Long-stalked Crane's-bill | 260 | 2019 |
| plant | Geranium dissectum | Cut-leaved Crane's-bill | 4229 | 2020 |
| plant | Geranium endressii | French Crane's-bill | 47 | 2017 |
| plant | Geranium endressii x versicolor = G. x oxonianum | a flowering plant | 4 | 2013 |
| plant | Geranium endressii x versicolor = G. x oxonianum | Druce's Crane's-bill | 19 | 2018 |
| plant | Geranium himalayense | Himalayan Crane's-bill | 1 | 2011 |
| plant | Geranium lucidum | Shining Crane's-bill | 1144 | 2019 |
| plant | Geranium macrorrhizum | Rock Crane's-bill | 6 | 2019 |
| plant | Geranium maderense | Giant Herb-Robert | 2 | 2007 |
| plant | Geranium molle | Dove's-foot Crane's-bill | 2201 | 2020 |
| plant | Geranium phaeum | Dusky Crane's-bill | 7 | 2019 |
| plant | Geranium pratense | Meadow Crane's-bill | 1169 | 2020 |
| plant | Geranium purpureum | Little-Robin | 31 | 2019 |
| plant | Geranium pusillum | Small-flowered Crane's-bill | 106 | 2019 |
| plant | Geranium pyrenaicum | Hedgerow Crane's-bill | 1274 | 2020 |
| plant | Geranium robertianum | Herb-Robert | 6268 | 2020 |
| plant | Geranium robertianum subsp. maritimum | a crane's-bill | 2 | 2014 |
| plant | Geranium rotundifolium | Round-leaved Crane's-bill | 626 | 2019 |
| plant | Geranium sanguineum | Bloody Crane's-bill | 56 | 2016 |
| plant | Geranium versicolor | Pencilled Crane's-bill | 15 | 2019 |
| plant | Geum chiloense | an avens | 1 | 1994 |
| plant | Geum rivale | Water Avens | 26 | 2019 |
| plant | Geum rivale x urbanum = G. x intermedium | Hybrid Avens | 1 | 1994 |
| plant | Geum urbanum | Wood Avens | 4752 | 2020 |
| plant | Ginkgo biloba | Ginkgo | 27 | 2016 |
| plant | Gladiolus communis | Eastern Gladiolus | 8 | 2019 |
| plant | Gladiolus communis subsp. byzantinus | a gladiolus | 1 | 2012 |
| plant | Glaucium flavum | Yellow Horned Poppy | 14 | 2008 |
| plant | Glaux maritima | Sea-milkwort | 245 | 2019 |
| plant | Glebionis coronaria | Crown Daisy | 3 | 1953 |
| plant | Glebionis segetum | Corn Marigold | 30 | 2019 |
| plant | Glechoma | a Glechoma species (unidentified) | 3 | 2011 |
| plant | Glechoma hederacea | Ground-ivy | 5306 | 2020 |
| plant | Gleditsia triacanthos | Honey locust | 21 | 2015 |
| plant | Glyceria | a sweet-grass (unidentified) | 299 | 2018 |
| plant | Glyceria declinata | Small Sweet-grass | 123 | 2013 |
| plant | Glyceria fluitans | Floating Sweet-grass | 1067 | 2017 |
| plant | Glyceria fluitans x notata = G. x pedicellata | Hybrid Sweet-grass | 17 | 1992 |
| plant | Glyceria maxima | Reed Sweet-grass | 642 | 2016 |
| plant | Glyceria notata | Plicate Sweet-grass | 539 | 2019 |
| plant | Glycine max | Soya-bean | 3 | 1930 |
| plant | Gnaphalium luteoalbum | Jersey Cudweed | 1 | 1933 |
| plant | Gnaphalium uliginosum | Marsh Cudweed | 221 | 2019 |
| plant | Gossypium hirsutum | Upland Cotton | 3 | 1938 |
| plant | Grindelia squarrosa | Curlycup Gumweed | 1 | 1922 |
| plant | Griselinia littoralis | New Zealand Broadleaf | 30 | 2015 |
| plant | Groenlandia densa | Opposite-leaved Pondweed | 83 | 2012 |
| plant | Guizotia abyssinica | Niger | 15 | 2018 |
| plant | Gunnera | a giant rhubarb (unidentified) | 2 | 2017 |
| plant | Gunnera tinctoria | Giant Rhubarb | 3 | 2014 |
| plant | Gymnadenia conopsea | Fragrant Orchid | 68 | 2017 |
| plant | Gymnadenia densiflora | a fragrant orchid | 2 | 2006 |
| plant | Gymnocarpium robertianum | Limestone Fern | 13 | 2012 |
| plant | Gymnocladus dioicus | Kentucky Coffee Tree | 1 | 2015 |
| plant | Gypsophila muralis | Annual Gypsophila | 1 | 1931 |
| sea-fan, sea anemone or jellyfish | Gonothyraea loveni | a Sea-fan/Sea Anemone/Jellyfish | 1 | 1937 |
| spider | Gibbaranea gibbosa | an orb-weaver spider | 7 | 2014 |
| spider | Gnathonarium dentatum | a money spider | 8 | 1999 |
| spider | Gonatium rubens | a money spider | 6 | 1987 |
| spider | Gongylidiellum vivum | a money spider | 2 | 2003 |
| spider | Gongylidium rufipes | a money spider | 3 | 1987 |
| tick or mite (acarine) | Gamasellus inermis | a mite | 1 | 1936 |
| true fly - | Gastrolepta anthracina | a parasitic fly | 3 | 1997 |
| true fly - | Geomyza balachowskyi | a fly | 4 | 2009 |
| true fly - | Geomyza subnigra | a fly | 1 | 2009 |
| true fly - | Geomyza tripunctata | a fly | 17 | 2016 |
| true fly - | Gigalimosina flaviceps | a lesser dung fly | 1 | 2003 |
| true fly - | Gonia divisa | a parasitic fly | 1 | 2013 |
| true fly - | Gonia picea | a parasitic fly | 1 | 2000 |
| true fly - | Goniocera versicolor | a parasitic fly | 1 | 1997 |
| true fly - | Graphogaster brunnescens | a parasitic fly | 1 | 1948 |
| true fly - | Graphomya maculata | a muscid fly | 11 | 2016 |
| true fly - | Gymnocheta viridis | a parasitic fly | 14 | 2018 |
| true fly - bot fly | Gasterophilus intestinalis | Horse Bot Fly | 1 | 2005 |
| true fly - cranefly | Gonomyia abbreviata | a cranefly | 1 | 2006 |
| true fly - (diptera) | Geranomyia unicolor | an insect - true fly (Diptera) | 1 | 2002 |
| true fly - (diptera) | Gymnoclasiopa plumosa | an insect - true fly (Diptera) | 1 | 2009 |
| true fly - (diptera) | Gymnomus caesius | an insect - true fly (Diptera) | 2 | 2003 |
| true fly - midge, gnat or mosquito | Geocrypta galii | a gall midge | 7 | 2001 |
| true fly - picture-winged, conopid or stilt-legged fly | Goniglossum wiedemanni | a gall fly | 3 | 2000 |