Acacia acuminata

Acacia acuminata Benth., London J. Bot . 1: 373 (1842)

Raspberry Jam , Jam

Shrub or tree (2–) 3–7 (–10) m high. New shoots appressed yellow-hairy. Branchlets ascending to erect, rarely pendulous, glabrous. Phyllodes linear to narrowly elliptic, apices curved-acuminate to caudate, (5–) 8–15 (–18) cm long, (1.5–) 2–8 (–10) mm wide, flat, straight to shallowly curved, ascending to erect or spreading at various angles, finely multistriate, green, glabrous except margins fringed with minute white hairs. Inflorescences simple; spikes sessile, (7–) 10–30 mm long (when dry), golden. Flowers mostly 4-merous; calyx dissected 1/2 or more. Pods linear, flat to variously raised over seeds, straight-edged to deeply constricted between seeds, (2–) 3–8 cm long, 2.5–7 mm wide, firmly chartaceous to thinly coriaceous-crustaceous. Seeds longitudinal, mostly compressed, oblong to elliptic or ovate, 2–4.5 mm long, 1.5–3 mm wide, 1–2.5 mm thick, black, shiny to slightly shiny, dark brown to black; aril membranous, white or creamy white.

Occurs in south-west W.A. where it extends from just north of the Murchison R. south to Borden and east to Balladonia; outlying populations occur near Yalgoo and Paynes Find. The eastern boundary of the main area of occurrence abuts that of A. burkittii which is common in the adjacent Arid Zone.

In Fl. Australia A. acuminata was treated as comprising two subspecies, subsp. acuminata and subsp. burkittii . In WATTLE these taxa are treated as separate species with A. acuminata comprising three main variants, "typical", "narrow phyllode" and "small seed". However, many plants from the Geraldton region cannot be satisfactorily accommodated by this classification as they seem to combine attributes of both A. acuminata and A. burkittii . These Geraldton variants (i.e. A. acuminata/burkittii variants 1 & 2) together with A. burkittii and the three main variants of A. acuminata are distinguished in the key below. The above taxonomy is based on a recent study by B.R.Maslin et al . (1999, unpublished), The Acacia acuminata (Jam) group: an analysis of variation to aid Sandalwood (Santalum spicatum) plantation research . (Report to the Sandalwood Business Unit: Department of Conservation and Land Management, Perth.).

Apart from its very close relationships with A. burkittii , A. acuminata has some affinities with A. drepanophylla , A. jibberdingensis and A. oldfieldii . However, based on the study by B.R.Maslin et al . ( loc. cit. ) the relationship between A. oldfieldii and A. acuminata is not as close as previously thought.

Acacia acuminata Benth. (typical variant)

Tall obconic shrub or tree 3–7 (–10) m high, few-branched at ground level or with a single, straight to sub-straight bole 0.3–1.5 (–2) m long. New shoots appressed yellow-hairy when first initiated. Branchlets ascending to erect, sometimes +/- pendulous, glabrous. Phyllodes linear to narrowly elliptic, apices curved-acuminate, (6–) 8–15 (–18) cm long, (3–) 4–8 (–10) mm wide, normally +/- straight to shallowly recurved, infrequently shallowly incurved, often spreading at various angles, finely multistriate, green, glabrous except margins fringed with minute white hairs. Inflorescences simple; spikes sessile, 15–30 mm long (when dry), golden. Flowers mostly 4-merous; calyx dissected 1/2 or more. Pods linear, flat but variably raised over seeds and shallowly to deeply constricted between them, rarely straight-sided, 4–8 cm long, 4–7 mm wide, firmly chartaceous to thinly coriaceous-crustaceous. Seeds longitudinal, mostly compressed, oblong or elliptic to ovate, 3–4.5 mm long, 2.3–3 mm wide, 1.8–2.5 mm thick, black, shiny to slightly shiny; aril white.

Acacia acuminata (typical variant) occurs in south-west W.A., principally in the western part of the wheatbelt from near Mingenew S to Borden and Ravensthorpe, with outliers at Peak Charles, about 130 km due NE of Ravensthorpe and near Paynes Find. The western boundary of the geographic range is located close to Dandaragan, Toodyay and Williams; the eastern boundary is located close to Wongan Hills, Kellerberrin, Corrigin and Ongerup but in the absence of fruits and further field studies it is difficult to precisely map this boundary where it abuts the range of A. acuminata (narrow phyllode variant) . The typical variant most commonly occurs in brown loamy clay or sandy loam (pH5.5–7) in lower parts of the landscape (often near water courses) or in low hilly country, in low eucalypt Woodland. It has also been recorded from shallow white sand over laterite near Corrigin, from clays and from around granite outcrops.

Within a single population of A. acuminata (typical variant) one can encounter plants with single boles (commonly to about 1–1.5 m long) or with 2–6 main stems arising from ground level. Pendulous forms are found scattered throughout the range and in most places occur at a low frequency within populations of typical individuals (which have ascending to erect branchlets and variously spreading to ascending phyllodes).

Acacia acuminata (typical variant) is usually distinguished (somewhat arbitrarily) from the narrow phyllode variant by its generally wider, often shallowly recurved and more spreading phyllodes, generally wider pods and often slightly wider and thicker seeds. In the central and northern wheatbelt the geographic ranges of these two variants abut and further field and laboratory studies are needed here to more confidentally separate the two taxa. Areas where both variants appear to occur include the Kellerberrin - Merredin and Wongan Hills regions.

Plants of A. acuminata (typical variant) with broadest phyllodes occur mostly in the Toodyay - Katanning region; in areas to the north and east of Toodyay the phyllodes appear to become progressively narrower (it is these latter forms which are often difficult to separate from the narrow phyllode variant of A. acuminata, especially when using herbarium material without pods). Specimens with consistently narrow phyllodes occur in southern areas from Borden to Ravensthorpe. Few specimens with atypically narrow phyllodes (3 mm wide) occur scattered elsewhere throughout the range in areas where normal broad phyllode individuals are found, e.g. Corrigin, Tambellup, New Norcia.

Acacia acuminata/burkittii (variant 2) is referred to in B.R.Maslin et al . (see reference above). These plants are common in the Northampton-Nabawa area but they range south to Eradu (Greenough R.) and Mt Fairfax, and north to near Ajana. They are very similar to A. acuminata (typical variant) except that they have larger, clearly turgid seeds (4–5 mm long, 3.5–4 mm wide, 3–3.5 mm thick); furthermore, their pods are always clearly rounded over the seeds. Acacia acuminata/burkittii (Variant 1) is noted under A. acuminata (narrow phyllode).

Type of accepted name

Swan R., W.A., J.Drummond s.n .; syn: ?K.

Synonymy

A. acuminata var. ciliata Meissner in J.G.C.Lehmann, Pl. Preiss . 1: 19 (1844). Type: near York, W.A., L.Preiss 934 ; lecto: NY, fide B.R.Maslin & R.S.Cowan, Nuytsia 9(3): 402 (1994); isolecto: A, G, GOET, HBG, L, LUND, MEL, MO, P, PERTH (Fragment ex MEL), STR.

Illustrations

M.Simmons, Acac. Australia 257 (1981); W.R.Elliot & D.L.Jones, Encycl. Austral. Pl . 2: 12 (1982); D.J.Boland et al ., Forest Trees Australia 4 edn, 151 (1984).

Representative collections

W.A.: Needilup Rd, 10 km N of intersection with Jerramungup – Needilup Rd, G.Craig 1561 (PERTH); 7.5 km SW of Dandaragan on road to Cataby, B.R.Maslin 7781 (CANB, MEL, PERTH); 6 km N of Bolgart on road to Calingiri, B.R.Maslin 7845 (BRI, PERTH) and 7853 (K, PERTH); c. 12 km W of Corrigin, 0.5 km S of Brookton-Corrigin Rd on Wickepin-Corrigin Rd, B.R.Maslin 7856 (MEL, PERTH); Wittenoom Bridge, 11 km S of York on road to Beverley, B.R.Maslin 7854 (NSW, PERTH);

Acacia acuminata Benth. (narrow phyllode variant)

Obconic or rounded shrub or small obconic tree commonly 2–5 m tall, sometimes (e.g. around granite rocks) tree 6–7 m, with 2–6 main stems arising from ground level or sometimes with a single bole up to 0.5 (–1) m. New shoots appressed yellow-hairy when first initiated. Branchlets glabrous. Phyllodes linear, apices curved-acuminate, 7–14 cm long, (1.5–) 2–4 mm wide, flat, ascending to erect, straight to very shallowly curved, finely multistriate, green, glabrous except margins fringed with minute white hairs. Inflorescences simple; spikes sessile, (7–) 10–15 (–20) mm, golden. Flowers mostly 4-merous; calyx dissected 1/2 or more. Pods linear, variously raised over the seeds and shallowly or sometimes moderately constricted between them, (2–) 3–8 cm long, 3–4(–5) mm wide, firmly chartaceous to thinly coriaceous-crustaceous. Seeds longitudinal, compressed, elliptic to oblong-elliptic, oblong-ovate or ovate, 3–4 mm long, 1.8–2.5 (–3) mm wide, 1–1.5 (–2) mm thick, shiny to sub-shiny, dark brown to black; aril white or creamy white.

Occurs in south-west W.A., in the northern, central and eastern wheatbelt region and extending just into the adjacent Arid Zone, from near Morawa SE to Balladonia; outlier populations appear to occur at Carracarrup Pool and on the Phillips River near Ravensthorpe. The northern boundary of the geographic range runs west of Wubin, and close to Beacon, Southern Cross and Kalgoorlie. The southern boundary runs close to Wubin, Kellerberrin, north of Hyden and south of Norseman. In the absence of fruits and more field studies it is difficult to precisely map the northern boundary where it abuts that of A. burkittii and the western boundary where it abuts and narrowly overlaps that of A. acuminata (typical variant) . Grows commonly on brown or red-brown loam or clay-loam flats (pH 6–7) in tall shrubland or open eucalypt woodland. It is also commonly found on sandy loam associated with granite rocks and commonly forms dense fringing communities around the base of these outcrops. It has also been recorded from low sand rises associated with salt lakes and appears slightly to moderately salt tolerant.

This variant is most closely related to A. acuminata (typical variant) and it is difficult to separate the two in the areas where their geographic ranges overlap. Furthermore, isozyme data suggests affinities with A. burkittii and the two taxa are easily confused unless in fruit.

Specimens with the widest pods (to 5 mm) and widest seeds (to 3 mm wide) often occur in well-watered sites such as the base of granite; these plants are often taller than those occurring elsewhere. Phyllodes can vary from 2–4 mm wide between plants within a single population.

Acacia acuminata/burkittii (variant 1) is referred to in B.R.Maslin et al . (see reference above). These plants are found in the Geraldton area, occurring near Mullewa, but particularly, from near Binnu north to near Nerren Nerren Station. Their phyllodes are very similar to those found on A. acuminata (narrow phyllode variant) while their seeds are similar to those found on A. burkittii except that they are more compressed, thus not as thick. Non-fruiting material from the above areas are difficult to name with confidence. Salient features of A. acuminata/burkittii variant 1 include the following: phyllodes straight to shallowly incurved, occasionally shallowly recurved, narrow (2–3 mm wide), seeds fairly turgid but compressed to some degree, (3.5–) 4–5 mm long, 2.5–3 (–3.5) wide and 1.5–2.5 mm thick, and pods 4–5 mm wide and clearly rounded over the seeds.

Representative collections

W.A.: Wanarra, near Lake Monger, C.A.Gardner 12467 (PERTH); Woodline, c. 85 km ENE of Norseman, G.J.Keighery 2972 (PERTH); Phillips River crossing, c. 15 km SW of Ravensthorpe on main road to Ongerup, L.Haegi 1041 (AD, PERTH); Coolgardie, July 1899, R.Helms s.n. (PERTH); about 26 km E of Kalannie, on Black Rd 1 km NE of Anderson Rd intersection, B.R.Maslin 7835 (MEL, PERTH).

Acacia acuminata Benth. (small seed variant)

Rounded multi-stemmed shrub or small tree (2–)3–5 m tall, with 3–6 main stems arising from ground level, sometimes (when a tree) with a short bole to about 1 m long, crown neat and compact and 2.5–6 m across. New shoots appressed golden hairy. Branchlets erect, glabrous. Phyllodes linear, apices narrowed to a curved, delicate, acuminate to caudate point, (5–)7–10 cm long, 3–6 mm wide, straight, ascending to erect, green, finely multistriate, glabrous except margins fringed with minute white hairs. Inflorescences simple; spikes sessile, 10–20 mm long, golden. Flowers mostly 4-merous; calyx dissected 1/2 or more. Pods linear, flat but prominently raised over seeds, scarcely constricted between seeds, 4–8 cm long, 2.5–3 mm wide, firmly chartaceous to thinly crustaceous, straight to shallowly curved, light brown,. Seeds longitudinal, compressed, oblong-elliptic to oblong or (when very short) almost square, 2–3 mm long, 1.5–1.8 mm wide, 1–1.5 mm thick, glossy, black; aril white, membranous, extending 1/3–1/2 way down one side of the seed.

Occurs in south-west W.A., predominantly in the northern wheatbelt and adjacent Arid Zone from about 50 km NE of Kalannie north to Jingemarra Station (N of Yalgoo) and east of Binnu; disjunct populations occur in south coastal regions south of Ongerup. Relatively few collections of this variant have been made to date but it is suspected that future sampling within the areas indicated above will show it to be more common than current collections indicate. The northern populations appear to occur in higher parts of the landscape in sometimes rocky, reddish or greyish brown fine loam (pH 5.5–6) or sandy clay, in open scrub or shrubland. The southern populations occur in granitic sandy loam in Eucalyptus woodland on gently undulating plains.

This variant is distinguished from all other variants of A. acuminata by a combination of its narrow pods with small seeds and its broad phyllodes with often protracted tips.

Representative collections

W.A.: Northern end of Black Rd, NE of Kalannie, 3 Sept. 1996, E.Hudson s.n. (PERTH); East of Binnu, Binnu East Rd 0.5 km E of Balla Whelarra Rd, B.R.Maslin 7796 (K, NSW, PERTH); 34.5 km W of Yalgoo along Mullewa-Mt Magnet road, M.McDonald and P.Butcher MM2590 (CANB, MEL, PERTH); 16 km S of Ongerup, N.Stevens KRN9521-1 (MELU, PERTH).

(BRM)

In Fl. Australia A. acuminata was treated as comprising two subspecies, subsp. acuminata and subsp. burkittii, but here in WATTLE they are treated as comprising separate species. This taxonomy is based on a recent study by B.R.Maslin et al . (1999, unpublished), The Acacia acuminata (Jam) group: an analysis of variation to aid Sandalwood (Santalum spicatum) plantation research . (Report to the Sandalwood Business Unit: Department of Conservation and Land Management, Perth.)

The information presented here originally appeared on the WATTLE CD-ROM which was jointly published by the Australian Biological Resources Study, Canberra, and the Department of Parks and Wildlife, Perth; it was produced by CSIRO Publishing from where it is available for purchase. The WATTLE custodians are thanked for allowing us to post this information here.