Crassula helmsii (New Zealand pygmy weed) on Derwentwater in the English Lake District. The view is of the lake's southern edge looking north. The bri

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Crassula helmsii (New Zealand pygmy weed) on Derwentwater in the English Lake District. The view is of the lake's southern edge looking north. The bright greens to the left are land plants including grasses and bracken (Pteridium aquilinum). They mark the position of the shore when the lake is full. Growing out into the lake is an infestation of C helmsii (yellow/green); it extends for about 40 metres along the shore, and about 15 metres into the lake. is an increasing environmental hazard to freshwater systems in the UK. As an aquatic plant, chemical control is difficult and undesirable; it can propagate itself from detached fragments, meaning that mechanical control methods often fail. It is banned from sale in the UK and is covered by Schedule 9 of the Wildlife and Countryside Act 1981, making causing it to grow in the wild an criminal offence

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Size: 5212px × 3468px
Photo credit: © DR JEREMY BURGESS/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: 9, alien, crassula, derwentwater, distrct, environmental, freshwater, hazard, helmsii, introduced, lake, national, park, pest, plant, pygmy, schedule, scheduled, system, weed, zealand