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Japanese knotweed

View or download sightings meta-data

Japanese Knotweed s.l. taxa

Large, bright green plants, with broad heart-shaped leaves. Often very tall from April onwards (in the South of the UK), plants may grow to more than 3 m (10 ft) tall, dwarfing most native plants and shrubs. Stems have the appearance of bamboo (tall, segmented and hollow), though they bear a superficial resemblance to rhubarb in colouration (red green) and texture (fleshy).

Often found in patches called stands, that may extend from just a few centimetres, to many metres in size. Stands are particularly common along railways, roads and in industrial areas. However, knotweed has a nasty habit of cropping up pretty much anywhere!

Hunt down Japanese knotweed!

Make a sighting! Read the description above — think you might have seen it? Snap it and send it (use our mobile app if you have a supported smartphone) — don't worry if you're not really sure; an expert will try and verify it by the picture.

Most recent

Japanese knotweed on 2012-08-17 19:37:28.086687

Japanese knotweed on 2012-08-17 19:37:28.086687

Japanese knotweed on 2012-08-17 19:26:06.285641

Japanese knotweed on 2012-08-17 19:26:06.285641

Japanese knotweed on 2012-08-13 17:23:37.960076

Japanese knotweed on 2012-08-13 17:23:37.960076

Japanese knotweed on 2012-08-13 17:11:29.910086

Japanese knotweed on 2012-08-13 17:11:29.910086

Japanese knotweed on 2012-08-13 14:02:56.161110

Japanese knotweed on 2012-08-13 14:02:56.161110

Japanese knotweed on 2012-08-13 14:00:42.531591

Japanese knotweed on 2012-08-13 14:00:42.531591

Japanese knotweed on 2012-07-25 15:50:00

Japanese knotweed on 2012-07-25 15:50:00

Japanese knotweed on 2012-07-25 15:00:00

Japanese knotweed on 2012-07-25 15:00:00

Japanese knotweed on 2012-07-21 19:37:23.888313

Japanese knotweed on 2012-07-21 19:37:23.888313

Japanese knotweed on 2012-07-21 15:46:03.546099

Japanese knotweed on 2012-07-21 15:46:03.546099

Japanese knotweed on 2012-07-21 15:24:59.262612

Japanese knotweed on 2012-07-21 15:24:59.262612

Japanese knotweed on 2012-06-19 13:55:16.118678

Japanese knotweed on 2012-06-19 13:55:16.118678

Japanese knotweed on 2012-06-19 13:38:56.301583

Japanese knotweed on 2012-06-19 13:38:56.301583

Japanese knotweed on 2012-06-17 11:58:22.759693

Japanese knotweed on 2012-06-17 11:58:22.759693

Japanese knotweed on 2012-06-02 18:27:04.389971

Japanese knotweed on 2012-06-02 18:27:04.389971

Japanese knotweed on 2012-06-02 18:25:54.254577

Japanese knotweed on 2012-06-02 18:25:54.254577

Japanese knotweed on 2012-06-02 14:53:00.310318

Japanese knotweed on 2012-06-02 14:53:00.310318

Japanese knotweed on 2012-06-02 14:32:46.333307

Japanese knotweed on 2012-06-02 14:32:46.333307

Japanese knotweed on 2012-05-27 15:26:52

Japanese knotweed on 2012-05-27 15:26:52

Japanese knotweed on 2012-05-26 16:55:26

Japanese knotweed on 2012-05-26 16:55:26

Japanese knotweed on 2012-05-26 14:38:51.796963

Japanese knotweed on 2012-05-26 14:38:51.796963

Japanese knotweed on 2012-05-15 10:04:26.311848

Japanese knotweed on 2012-05-15 10:04:26.311848

Japanese knotweed on 2012-05-12 12:12:25.880939

Japanese knotweed on 2012-05-12 12:12:25.880939

Japanese knotweed on 2011-10-16 16:33:50

Japanese knotweed on 2011-10-16 16:33:50

Japanese knotweed on 2011-10-12 16:20:50

Japanese knotweed on 2011-10-12 16:20:50

Japanese knotweed on 2011-10-12 13:54:08

Japanese knotweed on 2011-10-12 13:54:08

Japanese knotweed on 2011-10-10 12:00:00

Japanese knotweed on 2011-10-10 12:00:00

Japanese knotweed on 2011-10-09 19:00:03

Japanese knotweed on 2011-10-09 19:00:03

Japanese knotweed on 2011-10-09 17:12:40

Japanese knotweed on 2011-10-09 17:12:40

Japanese knotweed on 2011-10-09 16:17:31

Japanese knotweed on 2011-10-09 16:17:31

Japanese knotweed on 2011-10-08 13:17:22

Japanese knotweed on 2011-10-08 13:17:22

Japanese knotweed on 2011-10-08 12:48:13

Japanese knotweed on 2011-10-08 12:48:13

Sighting locations

Sighting history