Xanthandrus comtus
- Group
- True flies
- Peak month
- August
- Records since 2000
- 312
Xanthidium antilopaeum
- Group
- Seaweeds and algae
- Peak month
- June
- Records since 2000
- 63
Xanthocanace ranula
- Group
- True flies
- Peak month
- July
- Records since 2000
- 83
Xanthocarpia crenulatella
- Group
- Lichens
- Peak month
- June
- Records since 2000
- 927
Xanthocarpia marmorata
- Group
- Lichens
- Peak month
- July
- Records since 2000
- 297
Xanthochlorus ornatus
- Group
- True flies
- Peak month
- June
- Records since 2000
- 134
Xantholinus longiventris
- Group
- Beetles
- Peak month
- June
- Records since 2000
- 295
Xantholinus tricolor
- Group
- Beetles
- Peak month
- July
- Records since 2000
- 61
Xanthomonas campestris
- Group
- Microorganisms and protists
- Records since 2000
- 57
- Kingdom
- Bacteria
Xanthomus pallidus
- Group
- Beetles
- Peak month
- August
- Records since 2000
- 77
Xanthoparmelia loxodes
- Group
- Lichens
- Peak month
- September
- Records since 2000
- 286
Xanthoparmelia pulla
- Group
- Lichens
- Peak month
- May
- Records since 2000
- 121
Xanthoria aureola
- Group
- Lichens
- Peak month
- August
- Records since 2000
- 508
Xanthoria calcicola
- Group
- Lichens
- Peak month
- June
- Records since 2000
- 1,794
Xanthoriicola physciae
- Group
- Fungi
- Peak month
- March
- Records since 2000
- 608
Xanthostigma xanthostigma
- Group
- Other insects
- Peak month
- May
- Records since 2000
- 64
Xenasma tulasnelloideum
- Group
- Fungi
- Peak month
- January
- Records since 2000
- 60
Xenasmatella vaga
- Group
- Fungi
- Peak month
- October
- Records since 2000
- 143
Xenopelopia nigricans
- Group
- True flies
- Peak month
- March
- Records since 2000
- 490
Xenotypa aterrima
- Group
- Fungi
- Peak month
- May
- Records since 2000
- 99
Xerocomellus ripariellus
- Group
- Fungi
- Peak month
- September
- Records since 2000
- 54
Xerocomus ferrugineus
- Group
- Fungi
- Peak month
- September
- Records since 2000
- 206
Xerocomus silwoodensis
- Group
- Fungi
- Peak month
- August
- Records since 2000
- 55
Xerolycosa miniata
- Group
- Spiders
- Peak month
- July
- Records since 2000
- 158
Xerotrema quercicola
- Group
- Lichens
- Peak month
- November
- Records since 2000
- 69
Xestia stigmatica
- Group
- Butterflies and moths
- Peak month
- August
- Records since 2000
- 78
Xestophanes potentillae
- Group
- Bees, wasps and ants
- Peak month
- June
- Records since 2000
- 90
Xiphydria camelus
- Group
- Bees, wasps and ants
- Peak month
- June
- Records since 2000
- 76
Xylaria cinerea
- Group
- Fungi
- Peak month
- October
- Records since 2000
- 70
Xyleborinus saxesenii
- Group
- Beetles
- Peak month
- July
- Records since 2000
- 116
Xyleborus dispar
- Group
- Beetles
- Peak month
- June
- Records since 2000
- 55
Xylella fastidiosa
- Group
- Microorganisms and protists
- Peak month
- May
- Records since 2000
- 122
Xylocleptes bispinus
- Group
- Beetles
- Peak month
- May
- Records since 2000
- 78
Xylocoris cursitans
- Group
- True bugs
- Peak month
- July
- Records since 2000
- 101
Xylodon brevisetus
- Group
- Fungi
- Peak month
- April
- Records since 2000
- 66
Xylodon flaviporus
- Group
- Fungi
- Peak month
- October
- Records since 2000
- 72
Xylodon nesporii
- Group
- Fungi
- Peak month
- October
- Records since 2000
- 85
Xylodon radula
- Group
- Fungi
- Peak month
- January
- Records since 2000
- 287
Xylodon raduloides
- Group
- Fungi
- Peak month
- April
- Records since 2000
- 100
Xylographa lichen
- Group
- Lichens
- Peak month
- July
- Records since 2000
- 210
Xylographa lichen
- Group
- Lichens
- Peak month
- July
- Records since 2000
- 115
Xylographa lichen
- Group
- Lichens
- Peak month
- March
- Records since 2000
- 72
Xylophagus ater
- Group
- True flies
- Peak month
- May
- Records since 2000
- 431
Xylopsora friesii
- Group
- Lichens
- Peak month
- July
- Records since 2000
- 117
Xylota florum
- Group
- True flies
- Peak month
- July
- Records since 2000
- 58
Xylota jakutorum
- Group
- True flies
- Peak month
- June
- Records since 2000
- 561
Xysticus cristatus
- Group
- Spiders
- Peak month
- June
- Records since 2000
- 853
Xysticus erraticus
- Group
- Spiders
- Peak month
- June
- Records since 2000
- 104
Xysticus lanio
- Group
- Spiders
- Peak month
- May
- Records since 2000
- 59
Xysticus ulmi
- Group
- Spiders
- Peak month
- June
- Records since 2000
- 180