Zieria robertsiorum J.A.Armstr.

Armstrong, J.A. (2002) Australian Systematic Botany 15(3): 429-431. Type: L.J.Brass 20113, 7.ix.1948, Mt Finnegan, alt. 1000 m. Holo: BRI 134755; iso: CANB 186448: K.

Shrub to 2 m tall, forming an open compact bush. Stems erect to decumbent, wiry; branches with slight to prominent decurrent leaf bases, not glandular verrucose, indumentum of mainly stellate hairs every spread around branches, becoming glabrous with age.

Leaves palmately trifoliolate, not or very slightly glandular verrucose; petioles 2.5-10 mm long, glabrescent or having sparse to moderately dense stellate indumentum; leaflets elliptic to obovate, 6-28 mm x 2.5-11 mm, margins entire, flat or slightly recurved, with stellate hairs, midribs of abaxial surface raised.

Inflorescence axillary, shorter than or nearly equal to subtending leaf, usually 3-10-flowered, 1-3 flowers open at any time, not glandular verrucose, with stellate hairs; peduncle 1.5-12 mm long; bracts scale to leaf like, to 3 mm long. Sepals semi-circular to broadly deltate, 0.7-1 x 1-1.2 mm, not or slightly glandular verrucose, with simple and stellate hairs. Petals elliptic, 1.5-3.5 mm x 1.2-1.5 mm, white, with stellate hairs. Ovary glabrous or with stellate hairs.

Smooth, glabrous, 3 x 2 mm, base of style persistent forming a minute apical apiculum. Seeds oblong-ovoid, 2-2.5 x 1.2-1.5 mm, black, dull, longitudinally striate.

Cotyledons linear, elliptic or clavate, about 5-10 x 2-3 mm. First pair of leaves trifoliolate and opposite. At the tenth leaf stage: leaf trifoliolate, leaflet blades sessile or shortly stalked, aromatic when crushed, oil dots visible to the naked eye, lateral veins looping inside the blade margin. Compound leaf petiole grooved on the upper surface. Leaf and stem hairs small, mainly simple but with a few stellate hairs included.

Endemic to NEQ, found on Mt Finnegan, Malbon Thompson and Lamb Ranges, and on Hinchinbrook Island. Grows in crevices in windswept shrubland in open granite boulderfields or pavements in rainforest, above 1000 m alt.