Seasonal Wild Flowers

Latin name

Crassula helmsii

Other names

Australian Swamp Stonecrop

Family

Crassulaceae

Flowering season

June to August

English distribution

It is found throughout the country but is less common in

the North.

See the BSBI distribution map for New Zealand Pigmyweed

Habitat

It is a neophyte, which was introduced to the UK in the

1920s and first seen in the wild in the Southeast in the

1950s.

Since then, it has spread throughout the country.

It has entered the wild as an aquarium throw-out or

deliberately planted.

It grows submerged in fresh water, such as ponds, 

lakes, canals and reservoirs.

It also grows in ditches and muddy zones next to fresh

water.

It spreads rapidly and covers and chokes water bodies.

It is considered to be an undesirable, invasive alien.

Click on the following link for the NNSS – Non Native

Species Secretariat report for New Zealand Pigmyweed. 

Description

New Zealand Pigmyweed is a perennial herb which grows

submerged in water up to 3m deep and on soft mud.

The flowers are small - up to only 2mm. They have 4 white

petals, which are longer than the 4 sepals.

There are 4 stamens and 4 carpels.

Leaves are fleshy, linear to lanceolate and up to 2cm.

The stems are up to 30cm and can both trail in and arise,

erect from water.

On mud, the stems are flat against the surface with their

ends turning upwards.