Acacia gonocarpa F.Muell. s. lat., J. Proc. Linn. Soc ., Bot . 3: 136 (1859)
Erect, many-stemmed, spindly or spreading shrub to 2 m high, sometimes a tree to 3.5 m high, often with drooping branches and sparse canopy. Bark smooth but finely fissured at base of trunk. Branchlets angled or flattened, later terete; ridges minutely convoluted, translucent. Phyllodes single or sometimes in 2s or 3s, linear to narrowly elliptic, straight or upcurved, (1.5–) 5–12 (–14) cm long, 0.7–1.8 mm wide (2–8 mm wide in variants), with minute apical mucro, moderately stiff, with prominent, longitudinal midnerve. Spikes 1–3 in phyllode axils, to 3 cm long, interrupted, pale yellow or cream. Flowers 5-merous, rarely 4-merous; sepals free, 0.4–0.7 mm long, spathulate, glabrous; corolla 0.7–1 mm long, dissected to c. 1/2, the recurved petals with distinct midribs and thickened apices. Pods straight or curved, 2–8.5 cm long, 3–6 mm wide, woody, dark brown, with wings 2–4.5 mm wide and often convoluted. Seeds oblique, brown; funicle-aril straight, conical.
Occurs in northern N.T. from Melville Is. S to Darwin and Kakadu Natl Park, and in the Kimberley region of W.A. Grows in open eucalypt or mixed woodland, sometimes with Melaleuca nervosa , on top of sandstone escarpments or on the lower slopes or alluvial fans, sometimes on laterite, on sandy, gravelly soil. Flowers Oct.–Feb.
There are several variants allied to A. gonocarpa from W.A. and the N.T. requiring investigation; some of these resemble A. richardsii which is distinguished by its phyllodes having a rather well developed reticulum between the few longitudinal nerves (nerves all parallel or occasionally a few anastomoses developed in A. gonocarpa ). See A. tenuispica for discussion of relationships.
Type of accepted name
Gulf of Carpentaria, [N.T.], F.Mueller 7 ; syn: MEL 27221.
F.Mueller, Iconogr. Austral. Acacia dec. 11 [pl. 9] (1888); J.Brock, Top End Native Pl . 61 (1988); J.R.Wheeler, in J.R.Wheeler (ed.) et al ., Fl. Kimberley Region 321, fig. 93B (1992); C.R.Dunlop, G.J.Leach & I.D.Cowie, Fl. Darwin Region 2: 10, fig. 4 (1995).
W.A.: Mitchell Plateau, 9 km W of Mitchell Falls, B.R.Maslin 5087 (CANB, NSW, PERTH). N.T.: near Jabiru, W.Bishop 812 (AD, B, K, MEL, MO, NSW, TL, US); Melville Is., N.Byrnes 2793 (BRI, CANB, DNA, NSW); Cox Penin., Port Darwin, N.Holtze 2027 (NSW); near the end of Arnhem Hwy, Jabiru, M.D.Tindale 10007, K.Brennan & P.Munns (BRI, MEL, NSW, PERTH).