Introduced annual or biennial forb, sprawling. Leaves opposite each other, the leaf pairs united by a sheath at the base. Leaves 1-4.5cm long, less than 1mm wide, hairless, with a pointed tip or the tip drawn out into a short bristle. Flowers with 5 petals, white, or pink inside, in open groups at the tops of the stems.
Differs and from plants of Spergularia brevifolia that have coloured flowers in that the backs of the petals are white. It cannot be differentiated from plants of Spergularia brevifolia that have white flowers on characters that can be seen with the naked eye.
Differs from Spergularia diandroides in that the leaves are hairless and not sticky.
Definite differentiation between the species of Spergularia depends on microscopic examination of the seeds.
Descriptions of all species of Spergularia in this key are mostly taken from: Adams, L.G. West, J.G. & Cowley, K.J., (2008) Revision of Spergularia (Caryophyllaceae) in Australia. Australian Systematic Botany 21:251-270
PlantNET description with photo of dried plant: http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Spergularia~bocconei
Line drawing from Flora Palaestina. Scanned by Missouri Botanical Garden, USA