The flowers are white to yellow or greenish and arranged on the ends of branches in compact heads on a peduncle 2–13 mm (0.079–0.512 in) long.

Flowering mainly occurs from April to September and the fruit is a succulent, red nut.

[2][3][4][5] Pimelea microcephala was first formally described by Robert Brown in Prodromus Florae Novae Hollandiae in 1810.

[6][7] In 1983 S. Threlfall described two subspecies of P. microcephala in the journal Brunonia, and the names are accepted by the Australian Plant Census: Mallee rice-flower grows in shrubland, woodland and mallee, and is widespread in all mainland states of Australia and in the Northern Territory.

[3] It is found in the north-west of Victoria,[5] in inland New South Wales,[2][15] in the south of the Northern Territory[16] and in the Avon Wheatbelt, Carnarvon, Coolgardie, Gascoyne, Geraldton Sandplains, Great Victoria Desert, Mallee, Murchison Nullarbor, Pilbara and Yalgoo bioregions of Western Australia.