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Botanical name

Common name

Aboriginal name

Description

Characteristic features

Distribution and ecology

Flowering and fruiting period

Variation

Taxonomy

Notes

Conservation status

Origin of name

References

Acacia dictyophleba

Botanical name

Acacia dictyophleba F. Muell., Fragm. 3: 128 (1863)

Common name

Waxy Wattle (preferred common name), Feather-veined Wattle and Sand Hill Wattle

Aboriginal name

Langkur or Lungkun (Nyangumarta) and Jabandi (Thalanyji)

Description

Glabrous, resinous, spreading, rounded or 'v'-shaped shrubs to about 1-4 m tall, sparingly branched at or near ground level, the main stems straight, crowns dense or rather open and spindly. Bark light grey and smooth. Branchlets often sparsely tuberculate. New shoots shiny and light green (but becoming glaucous as surface wax dries), resinous but not sticky. Phyllodes oblanceolate, 5-8.5 cm long but smallest phyllodes on some plants can be 4 cm long, (9-) 10-25 (-28) mm wide on Pilbara plants, wide-spreading to ascending, coriaceous, somewhat shiny, the surface sometimes roughened by small tubercles on the nerves, dark green but soon aging grey-green or an attractive blue-grey, frequently with a white waxy surface bloom (especially over the nerves) due to dry resin; with 2-3 main longitudinal nerves and the minor nerves forming a coarse, conspicuous, open, net-like reticulum between them; apex obtuse, mucronulate. Gland on upper margin of phyllode 0-2 mm above pulvinus, elongate, an additional smaller gland adjacent to the apical mucro. Inflorescences simple; peduncles 10-25 mm long; heads scattered rather uniformly over the plants, globular or obloid, rather large (9-13 mm in diameter when dry), rich golden, densely 40-60-flowered. Flowers 5-merous; sepals united almost to apex. Pods narrowly oblong, flat but raised over seeds alternately on each side, 4-9 cm long, 10-16 mm wide, more or less papery, light brown, with a short basal stalk. Seeds transversely arranged in the pods, obloid to ellipsoid, 4-5 (-6) mm long, shiny, brown.

Characteristic features

Resinous shrubs. Phyllodes mostly 5-8.5 cm long and 10-25 mm wide, green but soon aging grey-green or attractive blue-grey, frequently with a whitish waxy surface bloom (especially over the nerves) due to dry resin, coriaceous, the surface sometimes roughened by small tubercles on the nerves, with 2 or 3 prominent longitudinal nerves and the minor nerves forming a coarse, open, net-like reticulum between them. Inflorescences simple, heads densely 40-60-flowered, 9-13 mm in diameter when dry. Pods broad (10-16 mm) and flat (but raised over seeds alternately on each side), more or less papery, with a short basal stalk. Seeds transverse in pods.

Distribution and ecology

Widespread in the northern and central arid zone where it extends from the Pilbara region of Western Australia eastwards through southern Northern Territory and north-eastern South Australia to southwest Queensland. Over this range it grows mainly in deep red or red-brown siliceous sand, on dunes or inter-dune areas, or sometimes on shallow stony soils. In the Pilbara A. dictyophleba is most common in the Hamersley Range and adjacent areas (Pannawonica to Newman), but it has also been recorded from east of Newman and from near the Yule and De Grey rivers in the vicinity of Port Hedland. It may form localized, dense regrowth stands following fire. It is normally found in stony loam, sandy loam or clay-loam on plains or in low undulating country, often associated with watercourses. It occurs in tall open shrubland or open low woodland with various acacias and eucalypts; spinifex is the most common ground cover but around the Yule River it grows in Cenchrus ciliata grassland.

Flowering and fruiting period

Plants with flowers have been collected between March and September but the main flowering flush is from May to early July. Mature pods occur from September to November (most in October). It is likely that the flowering (and probably fruiting) in this species is influenced by the timing and intensity of rainfall events.

Variation

The Pilbara plants are relatively invariate, however, a tall, spindly variant occurs in the northern Gibson and the Little Sandy deserts (see under A. dictyophleba in Maslin 2001 for discussion).

Taxonomy

Acacia dictyophleba is very closely related to A. melleodora and indeed, together with A. jensenii (which does not occur in the Pilbara region) and A. sabulosa , these taxa could possibly be regarded as subspecies of a single variable species (see Maslin 1999 for discussion; note that in this publication A. melleodora was treated as being the same as A. dictyophleba, however, in 2001 Maslin recognized A. melleodora as a species in its own right). Although A. melleodora and A. dictyophleba are treated here as separate species, the differences between them seem not to be great, and further study is needed to confirm their taxonomic status. Within the Pilbara region A. melleodora is most readily distinguished from A. dictyophleba by its generally smaller, less coarsely veined, smooth (i.e. not roughened by small protuberances) phyllodes, smaller, fewer-flowered heads, slightly narrower pods and slightly smaller seeds. Acacia melleodora is less common in the Pilbara than A. dictyophleba and although for the most part they have separate geographic ranges, they do come close together in the vicinity of Newman and the Yule River (but it is not known if they ever grow side by side). The following key is provided to distinguish the Pilbara plants of these two species.

Mature phyllodes mostly 5-8.5 cm long (a few may be as short as 4 cm), 10-28 mm wide; heads 9-13 mm in diameter when dry, 40-60-flowered; pods 10-16 mm wide; seeds obloid to ellipsoid, 4-5 mm long.

A. dictyophleba

Mature phyllodes mostly 3-4 cm long, 5-10 mm wide; heads 5-7 mm in diameter when dry, 30-40-flowered; pods 9-11 mm wide; seeds widely ellipsoid to +/-globose, 3-4 mm long.

A. melleodora

Notes

Acacia dictyophleba is used extensively in mine site rehabilitation programs in the Hamersley Range as a result of seed being easy to collect on large plants. Seeds germinate best after dormancy is broken through a hot water treatment and resultant germination may be as high as 98% (Fox and Dunlop 1983). It regenerates from seed after fire and also resprouts vigorously from the root stock.

Acacia dictyophleba is an attractive shrub with its large golden heads and its blue-grey foliage that is coated with a white bloom at certain times of the year. As such this species has potential as an ornamental for amenity planting in dry inland areas.

Chippendale and Jephcott (1963) suggest that A. dictyophleba in Northern Territory has moderate nutritive value but is normally not palatable, possibly due to its resinous nature; it is lightly grazed by cattle confined to spinifex country or in extremely dry periods (note: it is probable that these authors' concept of A. dictyophleba also included to A. melleodora).

The Nyangumarta people of the Shay Gap and Nimingarra area collected seed of A. dictyophleba which was ground to a paste with water and eaten. The phyllodes were also chewed like tobacco. In the Kimberley traditional owners from the Fitzroy Crossing area boil or soak the phyllodes of Acacia dictyophleba in water to make a weak tea which was drunk to alleviate the symptom of colds, coughs and headaches.

Conservation status

Not considered rare or endangered.

Origin of name

The botanical name is derived from the Greek words diktyon (a net) and phlebos (vein) in reference to the minor nerves of the phyllodes which form a coarse, open, net-like reticulum between the few main longitudinal nerves.

References

Chippendale, G.M. and Jephcott, B.R. (1963). Topfeed. The fodder trees and shrubs of Central Australia. Extension Article No. 5. pp. 51. (Northern Territory Administration, Animal Industry Branch: Alice Springs.)

Fox, J.E.D. and Dunlop, J.N. (1983). Acacia species of the Hamersley Ranges, Pilbara Region of Western Australia. Mulga Research Centre. Occasional Report No. 3. pp. 94. (Western Australian Institute of Technology: Bentley.)

Maslin, B.R. (1999). Acacia miscellany 16. The taxonomy of fifty-five species of Acacia, primarily Western Australian, in section Phyllodineae (Leguminosae: Mimosoideae). Nuytsia 12(3): 311-411.

Maslin, B.R. (2001). Acacia. In: A.E. Orchard and A.J.G. Wilson (eds) Flora of Australia. Volume 11A. pp. 536. (ABRS/CSIRO Publishing: Australia.)