Genus: 6 species.
Region: north shore of Sydney.
Habitat: dry sclerophyll forest; moist sandy loam soils, in sheltered aspects; on gentle slopes, below cliff-lines, near creeks in low open woodland; high soil moisture and relatively high soil-phosphorus levels.
BotanyErect, hairless shrub; 1.5 m tall; highly clonal; ability to resprout from its rootstock.
Stem: four-winged branches arising in pairs.
Leaves: opposite, at right angles to the next; oblong, toothed margins; leaf-midrib is channelled on the dark green upper surface, the lower surface paler.
Flowers: creamy-white; almost stalkless; sepals 4, triangular, erect, petal-like; blooming from August to November.
Fruit: winged nut, only known in the immature state, usually aborted before maturity.