Plant
Japanese knotweed
- Records in GBIF
- 3 445
- Fishing districts near where it occurs
- 1 400
- Most sightings
- September
About the species Japanese knotweed
About the species
An invasive herb from East Asia that forms dense stands up to three metres tall.
Where to find it by the water
Stream banks, gravel bars and roadsides by the water.
What this means for anglers
Strong rhizomes damage the bank and in a flood the fragments spread along the stream. Dense growth makes access to the water difficult. Do not carry cuttings.
When it is observed
Records by month in the areas around the fishing districts (GBIF).
- 70Jan
- 94Feb
- 66Mar
- 127Apr
- 289May
- 407June
- 394July
- 628Aug
- 729Sep
- 343Oct
- 231Nov
- 60Dec
In November the species is observed less than in the main season. Most records are from September.
The records come from people's observations and also reflect when and where observers move around. They are not a measurement of numbers or a guarantee of an encounter.
Where it was recorded
Fishing districts around which a record of this species exists. Sorted by number of records.
- Čierňanka č. 1 655
- Biely potok (Martin) 655
- Bitarovský potok 655
- Bystrica č. 1a 655
- Bystrica č. 1b 655
- Bystrica č. 2 655
- Čadečanka 655
- VN Šurabka 655
- Derivačný kanál Váhu 655
- Divina 655
- Dlhopolka 655
- Domanižanka č. 2 655
- VN Žilina 655
- Hradnianka 655
- Hričovský kanál č.2a 655
- Hričovský kanál č.2b 655
- Kornianka 655
- Kolárovický potok 655
- Kuneradský potok 655
- Kysuca č. 1 655
- Kysuca č. 2a 655
- Kysuca č. 2b 655
- Kysuca č. 3 655
- Manínsky potok – CHRO 655
- Milošovský potok 655
- Oščadnica 655
- Olešnianka 655
- Petrovička 655
- Pivovarský potok 655
- Povinský potok 655
- Porubský potok (Žilina) 655
- Predmieranka 655
- Radôstka č. 1 655
- Raková 655
- Rovnianka č. 1 655
- Rudinský potok 655
1,400 fishing districts in total, 36 shown. The number next to a fishing district is the number of records around it. Show on map
More species from the group plants
Photo credits
- Japanese knotweed: Photo: W.carter, CC0, Wikimedia Commons
- Common reed: Photo: W.carter, CC0, Wikimedia Commons
- Broadleaf cattail: Photo: Peter O'Connor aka anemoneprojectors from Stevenage, United Kingdom, CC BY-SA 2.0, Wikimedia Commons
- Yellow flag iris: Photo: Myrabella, CC BY-SA 3.0, Wikimedia Commons
- Common duckweed: Photo: author not stated, CC BY-SA 3.0, Wikimedia Commons
- Black alder: Photo: AnRo0002, CC0, Wikimedia Commons
- Himalayan balsam: Photo: H. Zell, CC BY-SA 3.0, Wikimedia Commons
The advice is general and does not replace the instructions of a doctor, rescuers, the site manager or the fishing regulations. Do not disturb protected species or dismantle their shelters.