
Erect Chickweed (Moenchia erecta)
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.
Growing on moist soil by a track in a nature reserve - Cardinia Reservoir Park

Moenchia erecta is a small annual plant in the family Caryophyllaceae. The plant is a common pasture weed native to Europe. It has been introduced elsewhere, including Australia and western North America, but it is not particularly invasive or competitive.