Acacia hendersonii Pedley, Austrobaileya 5(2): 309 (1999)
Spreading, glabrous, somewhat resinous shrub to 3 m tall. Branchlets slender, prominently ribbed, the ribs tuberculate. Phyllodes linear, (6–) 12–22 mm long, 0.7–1.1 mm wide, flat but thick, straight or slightly decurved at apex or distinctly sigmoid, abruptly contracted at base into a short pulvinus 0.2–0.5 mm long, obliquely mucronulate, one vein prominent on each face, yellow and translucent on young (dark) phyllodes, raised and opaque on older ones, a distinct narrow longitudinal depression between midrib and margins on dried phyllodes. Inflorescences simple, 1 per axil; peduncles 9–15 mm long, the base ebracteate; heads globular, 30–35-flowered. Flowers 5-merous; sepals united. Pods and seeds not seen.
This species is confined to the Blackdown Tableland, Qld, an isolated sandstone plateau with an interesting flora, including the endemic, or near-endemic, species Acacia gittinsii , A. storyi , and some eucalypts.
Acacia hendersonii is a member of the ‘ A. johnsonii group’. It most closely resembles A. johnsonii but differs in having glabrous branchlets, phyllodes with translucent midribs when young, abruptly contracted into a short pulvinus, with a smaller mucro and heads borne on longer peduncles. It also has some affinity with A. resinicostata but differs in its finer and longer phyllodes which are not sessile but which have pulvinuses 0.2–0.5 mm long.
Type of accepted name
Leichhardt District: Blackdown Tableland, c. 32 km SE of Blackwater, Qld, 11 Sept. 1971, R.J.Henderson, L.Durrington & P.R.Sharpe H1199; holo: BRI.
Acacia sp. (Blackdown Tableland R.J.Henderson+ H1199), L.Pedley (1997), in R.J.F.Henderson (ed.) Queensland Plants: Names and Distribution (Queensland Herbarium: Brisbane.)
[ A. resinicostata auct. non Pedley: L.Pedley, Austrobaileya 1: 253 (1980), p ro parte , as to Blackdown Tableland specimen cited.]
Qld: Blackdown Tableland, Gittins 1184 (BRI) and R.J.F.Henderson et al . H1077 (BRI); Blackdown Tableland, 2348’S 14908’E, Sep 1988, J.G.Simmons & M.H.Simmons 2058.
(LP & BRM)
This species was noted under A. resinicostata in the Fl. Australia treatment of Acacia. The above account of the species is based on the original description, which was provided for use in WATTLE by L.Pedley.