Acacia disparrima M.W.McDonald & Maslin, Austral. Syst. Bot. 13(1): 46, figs. 11 & 12 (2000)
Arborescent shrubs 3–5 m tall or small trees 3–9 (–12) m tall. Branchlets slender, angled at extremities (i.e. the uppermost few cm). Phyllodes dimidiate, subfalcate to falcate, 5–14 cm long, 0.4–3 cm wide, glabrous, pale green to dark grey-green; longitudinal nerves numerous and parallel (not anastomosing), (3–) 4–7 per mm, close together but with distinct inter-nerve spaces 0.1–0.2 (–0.3) mm wide. Inflorescences simple, 1–4 per axil; peduncles 3–8 mm long, glabrous; spikes 2–7 cm long, +/- interrupted, pale yellow (approaching cream) to lemon yellow, commonly sweetly scented. Flowers 5-merous; calyx gamosepalous; ovary glabrous. Pods narrowly oblong, straight to moderately curved, 2.5–9 cm long, 1–2 cm wide, dehiscing along dorsal suture, crustose, resinous (resin fragrant and often partially shedding at maturity), nerves oblique and not overly prominent. Seeds oblique to transverse, ellipsoid, obovoid or ovoid, 3–6 mm long, 2–3 mm wide, glossy, black to very dark brown, funicle/aril variable in colour and length.
Acacia disparrima mainly occurs in coastal and near-coastal regions of Qld and northern N.S.W., extending to the adjoining tablelands in N Qld.
Acacia disparrima is a member of the ‘ A. aulacocarpa group’ and until recently had been widely known as A. aulacocarpa . However, A. disparrima is recognized by its less acutely angled and commonly more slender branchlets, its pale green to medium grey-green foliage, paler-coloured spikes and less prominently nerved, crustose pods. Although both species are widespread and occupy a similar geographic range in Qld, A. disparrima is often locally abundant whereas A. aulacocarpa tends to have restricted local occurrences. A revision of the ‘ A. aulacocarpa group’ is presented in M.W.McDonald & B.R.Maslin, Austral. Syst. Bot. 13(1): 21–78 (2000).
Dried specimens of Acacia disparrima can sometimes be difficult to distinguish from A. lamprocarpa (which occurs in northern Australia); however, they are recognized by their longer spikes with the flowers more widely spaced, straight to moderately curved, crustose pods that dehisce along their dorsal suture and their longer aril/funicle.
An unresolved ‘dry land’ variant of A. disparrima occurs primarily in the lower Fitzroy River basin, between St. Lawrence and Gin Gin (Rockhampton region) associated with the dry, open woodlands which are common to the region (see McDonald and Maslin, loc. cit ., for discussion).
Two subspecies of A. disparrima are recognised and one of the most conspicuous character distinguishing them is the colour and length of the funicle/aril. However, as discussed by McDonald and Maslin ( loc. cit .) there is some variation in this character and not all specimens can be placed with certainty.
Spikes 1–2 per axil; funicle/aril distinctly grey or creamy grey and 2–5 folded below the seed (very rarely – encircling the seed); phyllodes pale grey-green to dark grey-green, minor nerves (3–) 4–5 per mm (Qld: Mackay S to Mylestrom, NSW)
Spikes 2–4 per axil; funicle/aril white (with a slight grey tinge) or cream, normally – encircling the seed; phyllodes green, pale grey-green or slightly subglaucous, minor nerves (4–) 5–7 per mm (NE Qld: Townsville N to Cape Melville)
Acacia disparrima M.W.McDonald and Maslin subsp. disparrima
Branchlets slender, angular at extremities. Phyllodes dimidiate, subfalcate or falcate, 5–12 cm long, 0.4–3 cm wide, pale grey-green to dark grey-green, minor nerves (3–) 4–5 per mm. Spikes 1–2 per axil. Funicle/aril normally 2–5-folded (rarely to encircling the seed as in subsp. calidestris ), creamy-grey to grey, ageing pale grey or greyish yellow.
Subspecies disparrima occurs predominantly in coastal and near-coastal areas with some extension into the adjoining tablelands, from Mackay in Qld S to Mylestrom (S of Coffs Harbour)in N.S.W. It is present on a number of continental islands in Qld between Rockhampton and Brisbane, e.g. Curtis, Hummocky, Facing, Fraser and South Stradbroke Islands. The subspecies is commonly associated with open forests, woodlands, the margins of sub-tropical, closed forest types and along disturbed roadsides. Flowers Jan.-May.
Plants in some coastal regions, such as Noosa, Yeppoon, Shoalwater Bay and Fraser Island, have strongly falcate, atypically narrow phyllodes often less than 1 cm wide.
Type of accepted name
0.6 km N of Burrum River crossing along Bruce Hwy, near turn-off to Howard, Qld, 13 Nov. 1996, M.W.McDonald 2385 & T.K.Vercoe ; holo: PERTH; iso: BRI, NSW.
A. aulacocarpa var. macrocarpa Benth., Fl. Austral . 2: 410 (1864). Type: Facing Island (also Keppel Bay, Shoalwater Bay and Broad Sound), Qld, Aug.-Sept. 1802 , R.Brown ; holo: K (specimen with Iter Australiense number 4368 - photograph seen).
A. leucadendron Cunn. ex Benth., London J. Bot . 1: 374 (1842), pro parte, not as to lectotype, as to paralectotype: Brisbane R., Fraser (K). (The lectotype of A . leucadendron , Hunter River, A.Cunningham , refers to a specimen of A. binervia (Wendl.) J.F.Macbr.)
[ A. aulacocarpa auct. non Cunn. ex Benth. : C.T.White, Proc. Roy. Soc. Qd 57: 22 (1946)]
J.H.Maiden Forest Fl. N.S.W . 3(7): pl. 103, as A. aulacocarpa ; M.Simmons, Acacias Australia 287(1981), as A. aulacocarpa ; J.W.Turnbull Multipurpose Australian trees and shrubs: lesser-known species for fuelwood and agroforestry . ACIAR Monograph No 1, p. 107 (1986), as A. aulacocarpa ; L.A.J.Thomson, Acacia aulacocarpa , A. cincinnata , A. crassicarpa and A. wetarensis an Annotated Bibliography (CSIRO: Melbourne.), p. 9, fig.1E (1994), pro parte, as to pod and seed, as A. aulacocarpa ; B.R.Maslin & M.W.McDonald, A Key to useful Australian Acacias for the Seasonally Dry Tropics (CSIRO: Melbourne.), p. 19 (1996), as A. aulacocarpa subsp. E; M.W.McDonald & B.R. Maslin, Austral. Syst. Bot. 13(1): 49, fig. 11 & 50, fig. 12 (2000).
N.S.W.: Iluka, opposite Golf Course near Hickey Street and Iluka-Woombah Rd , P.Kodela 341 (NSW); Pacific Highway, Maclean, D.Lea 907 (AD, CANB, DNA, HO, K, NSW, MEL, PERTH). Qld: Gin Gin Ck, 7 km NE of Gin Gin, A.R.Bean 8658 (BRI); 15.1 km SW of Gladstone, M.W.McDonald 2144 & P.A.Butcher (BRI, CANB); 43.9 km NE along Stanage Bay rd, M.W.McDonald 2383 & T.K.Vercoe (BRI, NSW, PERTH); about 13 km W of Noosa, near Tewantin, M.W.McDonald & B.R.Maslin BRM 7672 (BRI, CANB, K, NSW, PERTH); junction of turnoff to Pomona on Bruce Hwy, M.W.McDonald 2387 & T.K.Vercoe (ATSC, BRI, CANB, NSW, PERTH); South Stradbroke Island, on Broadwater side, T.J.McDonald 437 (NSW).
Acacia disparrima subsp. calidestris M.W.McDonald & Maslin, Austral. Syst. Bot. 13(1): 52, figs. 14 & 15 (2000)
Branchlets sometimes +/- pendulous, slender and brittle (snapping with a clean fracture). Phyllodes falcate to subfalcate, often long-tapered at apex, 8–14 cm long, 0.7–2 (–2.5) cm wide, green to pale grey-green or slightly subglaucous, commonly +/- milky green when dry, minor nerves (4–) 5–7 per mm. Spikes 2–4 per axil. Funicle/aril normally to encircling the seed (rarely 2–5-folded as in subsp. disparrima ), white (tinged grey) to cream, ageing pale yellow.
Occurs in NE Qld primarily on the Einasleigh Uplands from the Mt Carbine-Mt Molloy region S to Hervey Range W of Townsville. It also occurs in coastal areas N of Cooktown in the Cape Melville-Bathurst Bay region including Stanley Island. A southern outlier occurs at The Tableland, near Cranbourne Station, c. 150 km SW. Subspecies calidestris is usually found along seasonally dry creeks, diffuse drainage lines or run-on sites along roadsides in rocky, low, hilly or undulating terrain. Flowers March-June.
On Stanley Island, a continental island near Bathurst Head, subsp. calidestris grows in heath on exposed sandstone headlands where its maximum height is 1.5 m tall. By contrast the tallest plants of this subspecies occur in the Forty Mile Scrub region, south-west of Mount Garnet, where some plants may be up to 12 m tall with the trunks slightly fluted at their base.
Type of accepted name
21.5 km NW of Cooktown along rd to Hopevale, Qld, 7 Oct. 1996 , M.W.McDonald 2194 & P.A.Butcher ; holo: PERTH; iso: CANB, BRI.
L.A.J.Thomson, Acacia aulacocarpa , A. cincinnata , A. crassicarpa and A. wetarensis an Annotated Bibliography (CSIRO: Melbourne.), p. 9, fig. 1D (1994), and B.R.Maslin & M.W.McDonald, A Key to useful Australian Acacias for the Seasonally Dry Tropics (CSIRO: Melbourne.), p. 19 (1996), as A. aulacocarpa subsp. D; M.W.McDonald & B.R.Maslin, Austral. Syst. Bot. 13(1): 53, fig. 14 & 54, fig. 20 (2000).
Qld: Mt Mulligan, c. 2 km S of Mine Site along pipeline leading to falls on Richards Creek, J.R.Clarkson 5253 (BRI, CANB, DNA, K, MEL, NSW, PERTH, QRS); Cape Melville National Park, c. 11 km SSW of Cape Melville, J.R.Clarkson 9764 (BRI, NSW); Hervey Range, c. 50 km W of Townsville, M.W.McDonald & B.R.Maslin BRM 7627 (BRI, CANB, DNA, K, MEL, NSW, NY, PERTH); Forty Mile Scrub National Park, c. 65 km SSW of Mt Garnet on road to Hughenden, M.W.McDonald & B.R.Maslin BRM 7665 (BRI, NSW, PERTH).
This species is not included in the Fl. Australia treatment of Acacia . The above treatments are abstracted from original descriptions.