Acacia plectocarpa A.Cunn. ex Benth., London J. Bot . 1: 375 (1842)
Single-stemmed, shrub or tree to 9 (–13) m high. Bark flakey or fissured, grey to black. Branchlets angular towards apices, yellowish to brown, glabrous, often resinous. Phyllodes linear to very narrowly elliptic, flat, straight or curved, 9–26 cm long, 1.5–14 mm wide, thinly coriaceous, glabrous or with appressed hairs on nerves and margins, often resinous, with midnerve and 2 secondary nerves more prominent, the minor nerves 4–7 per mm, parallel, rarely anastomosing; gland 1, basal, inconspicuous. Spikes 1–3 per axil, (1.5–) 3–8 cm long, yellow. Flowers 5-merous; calyx 0.5–0.8 mm long, dissected to base, with few hairs; corolla 0.9–1.2 mm long, dissected to 1/2, glabrous or with sparse hyaline hairs mainly on tube; ovary densely pubescent. Pods linear to cultrate, straight, undulate, raised over seeds alternately on each side, 3–12 mm wide, brown, obscurely reticulate, resinous. Seeds oblique or transverse, broadly elliptic to orbicular, 1.8–3.8 mm wide, dark brown; pleurogram with pale halo; areole closed, depressed, sometimes paler than rest of seed.
A revision of Acacia plectocarpa and its closest allies, A. armitii and A. echinuliflora , is provided by G.J.Leach, Nuytsia 9: 351 (1994). Allied also to A. hemsleyi . In the absence of fruits, A. plectotocarpa specimens can be confused with A. torulosa , fide G.J.Leach, op. cit. 354. See also A. lentiginea .
There are 2 subspecies.
Phyllodes mostly 4.5–14 mm wide, 8–25 as long as wide; pods 6–12 mm wide; seeds 2–3.8 mm wide
Phyllodes 1.5–4.5 mm wide, 20–80 as long as wide; pods 3–4 mm wide; seeds 1.8–2 mm wide
Acacia plectocarpa A.Cunn. ex Benth. subsp. plectocarpa
Phyllodes linear to narrowly elliptic, straight or curved, 9.8–20 (–26) cm long, (4–) 4.5–14 mm wide (occasionally several phyllodes atypically wider), 10.5–35 (–43) times as long as wide, the nerves 4–6 per mm with 1–3 more prominent than the rest; pulvinus 1.5–4 mm long. Spikes bright yellow, 3–4 mm wide. Calyx 0.3–0.5 mm long. Pods 6–12 mm. Wide. Seeds transverse; funicle folded 4 times.
Widespread in north-western W.A. and N.T., N of 18S on the coast and up to 150 km inland. May possibly also occur in Qld - see below. Grows in sandy soil mostly near watercourses, in eucalypt woodland on sandstone or laterite. Flowers Mar.–July.
WATTLE Note. A recent Qld collection from "Burke district, 4 km from Hells Gate on Doumadgee Rd, P.I.Forster PIF 21074 (BRI), is distributionally anomalous and need confirming as subsp. plectocarpa .
Details of ecology, utilisation, etc. of A. plectocarpa subsp. plectocarpa are given in J.W.Turnbull (ed . ), Multipurpose Austral. Trees & Shrubs 182 (1986).
Type of accepted name
Cambridge Gulf, W.A., Sept. 1819, A.Cunningham 482 ; lecto: K, fide L.Pedley, Austrobaileya 1: 161 (1978); isolecto: NSW.
Racosperma plectocarpum (A.Cunn. ex Benth.) Pedley, Austrobaileya 2: 354 (1987); R. plectocarpum (A.Cunn. ex Benth.) Pedley subsp. plectocarpum , loc. cit . Type: as for accepted name.
Acacia numerosa Maiden & Blakely, J. Roy. Soc. Western Australia 13: 27, pl. 19, figs 5–9 (1928). Type: Napier, Broome Bay, W.A., 1910, G.F.Hill per A.J.Campbell 148 ; holo: NSW; iso: MEL, fragment & photo at PERTH.
J.H.Maiden & W.F.Blakely, loc. cit. ; J.Brock, Top End Native Pl . 72 (1988); J.R.Wheeler, in J.R.Wheeler (ed.) et al ., Fl. Kimberley Region 321, fig. 93E (1992); G.J.Leach, op. cit . 356, fig. 3A–C; C.R.Dunlop, G.J.Leach & I.D.Cowie, Fl. Darwin Region 2: 18, fig. 9 (1995).
W.A.: Denham R., W.V.Fitzgerald (NSW183370); 21 miles [33.8 km] E of Kununurra, I.V.Newman 626 (NSW); Wyndham, Sept. 1903, A.E.V.Woodroffe (NSW). N.T.: 10 km N of Pine Creek, M.D.Tindale 6003 & C.Dunlop (BRI, CANB, K, MEL, NSW, US); 3.8 km S of Edith R., M.D.Tindale 6021 & C.Dunlop (CANB, DNA, K, NSW, PERTH, UNSW).
Acacia plectocarpa subsp. tanumbirinensis (Maiden) Pedley, Austrobaileya 3: 216 (1990)
Phyllodes linear, straight, 9.5–19 cm long, 1.5–4.5 (–5) mm wide, (28–) 40–74 times as long as wide, the nerves 6–7 per mm with midnerve more prominent than the rest; pulvinus 0.8–1.6 mm long. Spikes pale yellow or yellow, 3.5–5 mm wide. Calyx 0.5–0.7 mm long. Pods 4.5–7 (–7.5) mm wide. Seeds oblique; funicle folded twice.
Predominently in the southern part of the Gulf of Carpentaria in the N.T. and near Westmoreland, Qld, close to the N.T. border. Grows on rocky hills or near watercourses in sandy alluvium. Flowers Apr.–July.
Type of accepted name
Sandstone country near Tanumbirini [Stn], N.T., 26 Mar. 1911, G.F.Hill 802 ; holo: NSW; iso: K, MEL, fragment & photo at PERTH.
Acacia tanumbirinensis Maiden (as ‘tanumbirinense’), in A.J.Ewart & O.B.Davies, Fl. N. Territory 338; 387, pl. 27E–H (1917); Racosperma plectocarpum subsp. tanumbirinense (Maiden) Pedley, Austrobaileya 2: 354 (1987). Type: as for accepted name.
J.H.Maiden, loc. cit .; G.J.Leach, op. cit ., 356, fig. 3D–F.
N.T.: 1 mile [1.6 km] NE [of] Borroloola on road to Bing Bong Stn, N.H.Henry 163 (BRI, DNA, MEL, NSW, PERTH); Cox R. Xing, Roper Bar to Borroloola road, G.J.Leach 3320 (BRI, DNA, MEL, NSW, NT, PERTH). Qld: 16 Mile Ck, 22 km from Westmoreland on road to Corinda, B.K.Simon & T.Farrell 3109 (BRI).