New Zealand pigmyweed

New Zealand pigmyweed

Crassula helmsii

This plant was first recorded in Ireland in 1984. It has spread very rapidly in watercourses in Britain and has the potential to do likewise here.

It forms dense submerged and emergent stands in ponds, small lakes and canals.

In suitable aquatic habitats the biomass produced is sufficient to eliminate native plants and create poorer conditions for macroinvertebrates and fish.