Sweet Alyssum, Sweet Alison
Introduced perennial forb to 40cm tall. Leaves basal and alternating up the stems, 2-4cm long, linear to flat, hairy, margins entire. Flowers fragrant, white, pink, or purple, with 4 petals, in groups at the tops of the stems, and in groups on stems originating at the bases of the leaves.
PlantNET description with line drawings: http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Lobularia~maritima