Dark giant horsefly
- Group
- True flies
- Peak month
- July
- Records since 2000
- 1,197
Species recorded in Powys
1,168 species
Powys — county
Marsh Valerian
- Group
- Flowering plants
- Peak month
- May
- Records since 2000
- 1,195
Yellow May Dun
- Group
- Mayflies
- Peak month
- April
- Records since 2000
- 1,186
Compressed Flapwort
- Group
- Liverworts
- Peak month
- July
- Records since 2000
- 1,181
Wormaldia occipitalis
- Group
- Caddisflies
- Peak month
- July
- Records since 2000
- 1,180
Meridion circulare
- Group
- Seaweeds and algae
- Peak month
- April
- Records since 2000
- 1,162
Large Brook Dun
- Group
- Mayflies
- Peak month
- April
- Records since 2000
- 1,160
Apricot Club
- Group
- Fungi
- Peak month
- October
- Records since 2000
- 1,150
Bloomed Furrow Bee
- Group
- Bees, wasps and ants
- Peak month
- August
- Records since 2000
- 1,131
String-of-sausage lichen
- Group
- Lichens
- Peak month
- March
- Records since 2000
- 1,125
Small Dark Olive
- Group
- Mayflies
- Peak month
- September
- Records since 2000
- 1,117
Jagged Notchwort
- Group
- Liverworts
- Peak month
- July
- Records since 2000
- 1,104
Blackish Puffball
- Group
- Fungi
- Peak month
- October
- Records since 2000
- 1,080
Cladonia subcervicornis
- Group
- Lichens
- Peak month
- May
- Records since 2000
- 1,076
Gyrographa gyrocarpa
- Group
- Lichens
- Peak month
- May
- Records since 2000
- 1,071
Cocconeis pediculus
- Group
- Seaweeds and algae
- Peak month
- September
- Records since 2000
- 1,067
Deceptive Earthtongue
- Group
- Fungi
- Peak month
- November
- Records since 2000
- 1,066
Tufted bulrush
- Group
- Flowering plants
- Peak month
- June
- Records since 2000
- 1,055
Bucklandiella affinis
- Group
- Mosses
- Peak month
- May
- Records since 2000
- 1,048
Slender-footed Robberfly
- Group
- True flies
- Peak month
- June
- Records since 2000
- 1,041
Achnanthes pyrenaica
- Group
- Seaweeds and algae
- Peak month
- September
- Records since 2000
- 1,027
Gomphonema olivaceum
- Group
- Seaweeds and algae
- Peak month
- April
- Records since 2000
- 1,026
Ivory Bonnet
- Group
- Fungi
- Peak month
- November
- Records since 2000
- 1,003
Floating Hook-moss
- Group
- Mosses
- Peak month
- July
- Records since 2000
- 983
Tall Thyme-moss
- Group
- Mosses
- Peak month
- April
- Records since 2000
- 976
Melosira varians
- Group
- Seaweeds and algae
- Peak month
- September
- Records since 2000
- 956
Synedra ulna
- Group
- Seaweeds and algae
- Peak month
- September
- Records since 2000
- 956
Silky Pinkgill
- Group
- Fungi
- Peak month
- October
- Records since 2000
- 947
Awl-leaved Screw-moss
- Group
- Mosses
- Peak month
- April
- Records since 2000
- 946
Hill Notchwort
- Group
- Liverworts
- Peak month
- July
- Records since 2000
- 945
Scarlet Caterpillarclub
- Group
- Fungi
- Peak month
- October
- Records since 2000
- 943
Brunton's Dog-tooth
- Group
- Mosses
- Peak month
- April
- Records since 2000
- 937
Glutinous Waxcap
- Group
- Fungi
- Peak month
- October
- Records since 2000
- 927
Bembidion atrocaeruleum
- Group
- Beetles
- Peak month
- June
- Records since 2000
- 926
Dwarf Flapwort
- Group
- Liverworts
- Peak month
- July
- Records since 2000
- 911
Golden Spindles
- Group
- Fungi
- Peak month
- October
- Records since 2000
- 908
Hildenbrandia rivularis
- Group
- Seaweeds and algae
- Peak month
- July
- Records since 2000
- 903
Eunotia exigua
- Group
- Seaweeds and algae
- Peak month
- September
- Records since 2000
- 895
Sellaphora saugerresii
- Group
- Seaweeds and algae
- Peak month
- September
- Records since 2000
- 888
Gomphonema minutum
- Group
- Seaweeds and algae
- Peak month
- September
- Records since 2000
- 877
Varnished Hook-moss
- Group
- Mosses
- Peak month
- September
- Records since 2000
- 873
Bird's-foot Wing-moss
- Group
- Mosses
- Peak month
- July
- Records since 2000
- 863
Nitzschia fonticola
- Group
- Seaweeds and algae
- Peak month
- September
- Records since 2000
- 862
Opal Thread-moss
- Group
- Mosses
- Peak month
- July
- Records since 2000
- 839
Gomphonema exilissimum
- Group
- Seaweeds and algae
- Peak month
- September
- Records since 2000
- 833
Hannaea arcus
- Group
- Seaweeds and algae
- Peak month
- April
- Records since 2000
- 830
Box-leaf honeysuckle
- Group
- Flowering plants
- Peak month
- May
- Records since 2000
- 829
Atherix marginata
- Group
- True flies
- Peak month
- September
- Records since 2000
- 812