Opercularia Gaertn.

Heads grouped together into a compound head. Plant usually foetid Opercularia
Plants glabrous or scabrous-pubescent, with straggling branches
Seeds very much pitted, rugose on the inner face, without longitudinal ridges. Leaves linear to linear-lanceolate, up to 30 mm long. Stems c. 20 cm long. Widespread (uncommon in Blue Mts). Heath; DSF; grasslands. Fl. spring–summer Opercularia diphylla
Seeds transversely wrinkled with 2 prominent smooth longitudinal ridges