Acacia macradenia Benth., in T.L.Mitchell, J. Exped. Trop. Australia 360 (1848)
Shrub or tree 3–5 m high. Branchlets pendulous to subpendulous, flexuose, glabrous. Stipules to 5 mm long, reflexed, indurate at maturity. Phyllodes patent to reflexed, narrowly elliptic to narrowly oblong, 13–25 cm long, 1–2.5 cm wide, narrowed and curved at base, commonly acuminate, glabrous; midrib prominent and contiguous with abaxial margin near base; lateral nerves diverging widely from midrib and anastomosing; gland 0–10 mm above pulvinus, elongate, sometimes 1 or 2 additional smaller glands above middle. Inflorescences 8–15-headed racemes, prolific in upper axils; raceme axes 2–5 cm long, glabrous; peduncles 3–6 mm long, glabrous; heads globular, densely 35–50-flowered, golden. Flowers 5-merous; sepals c. 3/4-united. Pods to 12 cm long, c. 5 mm wide, thinly coriaceous, glabrous. Seeds longitudinal, oblong, c. 4 mm long; funicle-aril about as long as seed.
Widespread in south-eastern Qld from Clermont to Surat with a northern outlier at Torrens Creek, NE of Hughenden. Grows in stony and sandy soil, often near creeks, in woodland or sometimes vine thicket.
Hybrids between A. macradenia and A. bancroftiorum are noted by L.Pedley, Austrobaileya 1: 95 (1978) and 1: 275 (1979). These hybrids resemble A. holotricha , an uncommon species distinguished by its overall denser indumentum. Hybrids between A. macradenia and A. fimbriata are known in cultivation (e.g. B.R.Maslin 6094 , PERTH).
The pods and seeds described by G.Bentham, Fl. Austral . 2: 362 (1864) under A. macradenia are those of A. fasciculifera , fide F.Mueller, S. Sci. Rec. 2 (7): 150 (1882).
A decorative species, common in cultivation in eastern Australia.
Type of accepted name
Bed of rivers, subtropical New Holland [Maranoa R., near ‘Forest Vale’ HS, Qld, fide L.Pedley, Austrobaileya 1: 270, 1980], 31 Aug. 1846, T.L.Mitchell ‘296’ ; holo: K n.v. , fide L.Pedley, op. cit ., 269; probable iso: NSW.
Racosperma macradenium (Benth.) Pedley, Austrobaileya 2: 352 (1987). as for accepted name.
F. von Mueller, Iconogr. Austral. Acacia dec. 5 [pl. 7] (1887); M.Simmons, Acacias Australia 177 (1981).
Qld: 34.9 km along highway from Morven to Roma, N.Hall 82/18 (NSW, PERTH); Blackdown Tableland, 19 km SSE of Bluff, R.W.Johnson 1013 (BRI); Alpha- Tambo, J. & M.Simmons 1103 (PERTH).