Zieria exsul is a plant in the citrus family Rutaceae and is endemic to a small area of southeast Queensland. It is an open, straggly shrub with hairy branches, three-part leaves and white flowers in groups of up to twelve, the groups longer than the leaves and each flower with four petals and four stamens.
Zieria exsul is an open, weak, straggly shrub which grows to a height of 60sigfig=1NaNsigfig=1 and has relatively smooth but hairy branches. The three-part leaves have a petiole NaNsigfig=1NaNsigfig=1 long and a central leaflet which is egg-shaped, NaNsigfig=1NaNsigfig=1 long, NaNsigfig=1NaNsigfig=1 wide with the other two leaflets slightly smaller. The upper surface of the leaf is slightly hairy but the lower surface is densely hairy with woolly, star-shaped hairs.[1]
The flowers are white and are arranged singly or in groups of up to twelve in leaf axils on a mostly glabrous stalk NaNsigfig=1NaNsigfig=1 long, the groups longer than the leaves. The sepals are more or less triangular, about 1sigfig=1NaNsigfig=1 long and wide and the four petals are elliptic in shape, about 2sigfig=1NaNsigfig=1 long and 1.5sigfig=1NaNsigfig=1 wide. The four stamens are less than 1sigfig=1NaNsigfig=1 long. Flowering occurs mostly occurs between August and September and is followed by fruit which is a glabrous capsule, about 3sigfig=1NaNsigfig=1 long and 2sigfig=1NaNsigfig=1 wide. This species is similar to Zieria compacta except that it is a more straggly shrub and has glabrous flower stalks.
Zieria exsul was first formally described in 2007 by Marco Duretto and Paul Irwin Forster from a specimen collected in Caloundra and the description was published in Austrobaileya.[2] The specific epithet (exsul) is a Latin word meaning "a banished person"[3] referring to this species having been displaced from most of its probable former range.
This zieria grows in woodland and wallum heathland near Buderim and Caloundra in the South East Queensland biogeographic region.
Zieria exsul is listed as "endangered" under the Queensland Nature Conservation Act 1992.[4]