Erect Chickweed

Description:

Growing close to the ground, this plant had slender erect stems with solitary 4-petalled white flowers. The most attractive feature of the flower were the four green sepals that alternated with the white petals. The sepals were a third longer than the petals and had colourless membranous margins (scarius).
The plant had basal branches and few leaves were seen at nodes.

Habitat:

Growing on moist soil by a track in a nature reserve - Cardinia Reservoir Park

Notes:

I couldn't get better shots of the plant which was disappointing, but I am happy that I got to see a naturalised "weed" that is so striking.
Family: Caryopllaceae