Crassula helmsii in the British Isles

Crassula helmsii, commonly known as New Zealand Pigmyweed or Australian Swamp Stomecrop, is a succulent perennial herb from Australasia that in recent decades has become an invasive plant in the British Isles. It can occur in a wide range of habitats, including ponds, lakes, gravel pits and other static waterbodies, and is now present at