Least duckweed

Lemna minuta

Description:
Least Duckweed
Facts:

One of the smallest of the duckweeds found in the UK (the darker plants in the image are Wolffia columbiana another duckweed) it forms dense mats on ponds and watercourses that can block virtually all the light to aquatic plants beneath them.

Introduced:

1977
Origin:
North and South America
Location:
Still and slow moving waterways in England, Wales and Channel Isles
Status:
Increasing
Problems:
Comments:
Chokes waterways and outcompetes native vegetation