Zebra Mussel
- Group
- Molluscs
- Records since 2000
- 3,352
- Scientific name
- Dreissena polymorpha
Brown sedge
- Group
- Caddisflies
- Records since 2000
- 3,323
- Scientific name
- Anabolia nervosa
Bark Barnacles
- Group
- Lichens
- Records since 2000
- 3,317
- Scientific name
- Thelotrema lepadinum
Polypody
- Group
- Ferns and horsetails
- Records since 2000
- 3,274
- Scientific name
- Polypodium vulgare
Nettle weevil
- Group
- Beetles
- Records since 2000
- 3,260
- Scientific name
- Phyllobius pomaceus
Pterostichus strenuus
- Group
- Beetles
- Records since 2000
- 3,248
- Peak month
- May
Golden-scale male fern
- Group
- Ferns and horsetails
- Records since 2000
- 3,232
- Scientific name
- Dryopteris affinis
Club-tailed Dragonfly
- Group
- Dragonflies and damselflies
- Records since 2000
- 3,201
- Scientific name
- Gomphus vulgatissimus
Sanicle
- Group
- Flowering plants
- Records since 2000
- 3,193
- Scientific name
- Sanicula europaea
Common Sun Beetle
- Group
- Beetles
- Records since 2000
- 3,170
- Scientific name
- Amara aenea
Sea-kale
- Group
- Flowering plants
- Records since 2000
- 3,139
- Scientific name
- Crambe maritima
Caspian mud shrimp
- Group
- Crustaceans
- Records since 2000
- 3,122
- Scientific name
- Chelicorophium curvispinum
Fluffy Dust Lichen
- Group
- Lichens
- Records since 2000
- 3,067
- Scientific name
- Lepraria lobificans
Spotted Medick
- Group
- Flowering plants
- Records since 2000
- 3,062
- Scientific name
- Medicago arabica
Dartford Warbler
- Group
- Birds
- Records since 2000
- 3,048
- Scientific name
- Sylvia undata
Columbine
- Group
- Flowering plants
- Records since 2000
- 3,047
- Scientific name
- Aquilegia vulgaris
Sulphur Dust Lichen
- Group
- Lichens
- Records since 2000
- 3,041
- Scientific name
- Psilolechia lucida
Temminck's Stint
- Group
- Birds
- Records since 2000
- 3,040
- Scientific name
- Calidris temminckii
Yellow Map Lichen
- Group
- Lichens
- Records since 2000
- 3,025
- Scientific name
- Rhizocarpon geographicum
Rose Chafer
- Group
- Beetles
- Records since 2000
- 3,010
- Scientific name
- Cetonia aurata
Abax parallelepipedus
- Group
- Beetles
- Records since 2000
- 3,005
- Peak month
- May
Achelia echinata
- Group
- Other invertebrates
- Records since 2000
- 2,970
- Peak month
- May
Silpha atrata
- Group
- Beetles
- Records since 2000
- 2,964
- Peak month
- May
Common Dainty
- Group
- True flies
- Records since 2000
- 2,957
- Scientific name
- Baccha elongata
Bitter fluff-wart
- Group
- Lichens
- Records since 2000
- 2,956
- Scientific name
- Lepra amara
Common Leaf Weevil
- Group
- Beetles
- Records since 2000
- 2,907
- Scientific name
- Phyllobius pyri
Spotted Crane Fly
- Group
- True flies
- Records since 2000
- 2,905
- Scientific name
- Nephrotoma appendiculata
Tubificoides amplivasatus
- Group
- Worms (annelids)
- Records since 2000
- 2,899
- Peak month
- May
Small Nettle Weevil
- Group
- Beetles
- Records since 2000
- 2,889
- Scientific name
- Nedyus quadrimaculatus
Yellow spotted sedge
- Group
- Caddisflies
- Records since 2000
- 2,862
- Scientific name
- Philopotamus montanus
Pacific oyster, Japanese oyster, Miyagi oyster, Portuguese oyster, Pacific cupped oyster, Immigrant oyster, Giant pacific oyster, Giant oyster, Giant cupped oyster
- Group
- Molluscs
- Records since 2000
- 2,859
- Scientific name
- Magallana gigas
Nit Beard Lichen
- Group
- Lichens
- Records since 2000
- 2,839
- Scientific name
- Usnea subfloridana
Pertusaria pertusa
- Group
- Lichens
- Records since 2000
- 2,835
- Peak month
- May
Eyed Ladybird
- Group
- Beetles
- Records since 2000
- 2,834
- Scientific name
- Anatis ocellata
Rock Crane's-bill
- Group
- Flowering plants
- Records since 2000
- 2,829
- Scientific name
- Geranium macrorrhizum
Plea minutissima
- Group
- True bugs
- Records since 2000
- 2,819
- Also known as
- a pygmy backswimmer
Microvelia reticulata
- Group
- True bugs
- Records since 2000
- 2,763
- Peak month
- May
Polychrome harp ground beetle
- Group
- Beetles
- Records since 2000
- 2,760
- Scientific name
- Harpalus affinis
Winter Creeper
- Group
- Flowering plants
- Records since 2000
- 2,746
- Scientific name
- Euonymus fortunei
Soft Shield-fern
- Group
- Ferns and horsetails
- Records since 2000
- 2,731
- Scientific name
- Polystichum setiferum
Rhipidia maculata
- Group
- True flies
- Records since 2000
- 2,713
- Peak month
- May
Mexican Fleabane
- Group
- Flowering plants
- Records since 2000
- 2,685
- Scientific name
- Erigeron karvinskianus
Limnephilus affinis
- Group
- Caddisflies
- Records since 2000
- 2,681
- Peak month
- May
Anaspis maculata
- Group
- Beetles
- Records since 2000
- 2,678
- Peak month
- May
Powder-headed Tube Lichen
- Group
- Lichens
- Records since 2000
- 2,663
- Scientific name
- Hypogymnia tubulosa
Thistle Tortoise Beetle
- Group
- Beetles
- Records since 2000
- 2,654
- Scientific name
- Cassida rubiginosa
Wood Melick
- Group
- Flowering plants
- Records since 2000
- 2,652
- Scientific name
- Melica uniflora
Massive horny sponge
- Group
- Sponges
- Records since 2000
- 2,650
- Scientific name
- Polymastia boletiformis