Acacia stenophylla varies in characteristic and size, from a rounded, multi stemmed shrub to a spreading tree.^[4] A. stenophylla grows from 4–20 m (13–66 ft) tall,^[4] often stemming into branches at the trunk from about 1 m (3.3 ft).^[5] Bark is dark-grey to blackish and rough, branchlets are smooth to sericeous and sometimes angular.^[4]

The phyllodes are strap-like, 15–40 cm (5.9–15.7 in) long, 2–10 mm (0.079–0.394 in) wide, straight to slightly curved, slightly rough, free from hair or very finely puberulous, acute to acuminate, apex is often strongly curved.^[4] Veins are copious and closely parallel.^[6]

Racemes are 3–5-headed, stems 2–15 mm (0.079–0.591 in) long and are slightly rough or with appressed minute hairs.^[4] Peduncles are 6–13 mm (0.24–0.51 in) long.^[4] Flower heads are creamy-white to pale yellow in colour, spherical and 6–9 mm (0.24–0.35 in) in diameter.^[4] Flowers are 5-merous, sepals three-quarters united.^[4]

Pods are moniliform, up to 26 cm (10 in) long, 8–12 mm (0.31–0.47 in) wide, woody-leathery textured, smooth except micro-puberulous between seeds.^[4] Seeds are longitudinal, elliptic, 7–9 mm (0.28–0.35 in) long, dark brown, lacking aril, funicle enlarged, are folded at the seed apex.^[4] Flowering time is often irregular, although mainly occurring in autumn.^[4]

Acacia stenophylla is highly salt tolerant and moderately frost and drought tolerant.^[7] The average minimum annual rainfall that the tree needs is around 400 mm (16 in) per year.^[8]

Acacia stenophylla is predominantly distributed in central and eastern Australia.^[2] It is also found infrequently in arid regions of Western Australia and towards the southern end of the western coast, although very rarely.^[2]

A. stenophylla is found from the Murray River in South Australia and Victoria to western New South Wales, Northern Territory, Queensland, with a small population also occurring in Western Australia.^[2]

Latitude - Main occurrence: 23–33°S^[2]

Range: 17–36°S ^[2]

Altitude - Main occurrence: 50–325 m^[2]

Range: near sea level to 625 m^[2]

Climate edit

Acacia stenophylla is most commonly found in a warm arid climatic zone.^[2] Acacia stenophylla tends to grow to a larger size in semi-arid climates which exist in New South Wales and Queensland.^[2] The species also expands into the sub-humid zone in Queensland.^[2]

Disregarding the species far southern distribution, the mean maximum temperature of the warmest month is 35–38 °C and the mean minimum of the coolest month 4–7 °C.^[2] There are, on average, about 110–130 days per year over 32 °C and 15–50 days over 38 °C.^[7]

Acacia stenphylla is subject to experiencing 1–20 heavy frosts per year, on average.^[2] The species withstands a variable range of rainfall frequency.^[2] Rainfall is often amplified by groundwater or periodic flooding.^[7]

Physiography and soils edit

Acacia stenophylla is common throughout the Interior Lowlands physiographic division.^[2] It is often present on plains and gentle slopes and is common on the banks of watercourses, river flood plains, and depressions.^[2] The soils are predominantly fine-textured alluvials, red sandy clay and grey cracking clays.^[2] Soils often have a high pH and may be more saline in the lower horizons.^[2]

Vegetation type edit

Acacia stenophylla occurs in ribbon-like stands along watercourses, often as a part of eucalyptus dominated open-forest, woodland or low woodland.^[2] The species can be present in the understorey, often with Acacia salicina and Acacia pendula.^[2] It can also occur alongside Eucalyptus populnea and Casuarina cristata, but commonly grows independently alongside watercourses in semi-arid areas.^[9]

Utilisation and uses edit

Acacia stenophylla is rarely utilised by cattle,^[10] but it is palatable to sheep.^[11] Seeds and pods of Acacia stenophylla were roasted and used by Indigenous Australians as a food source.^[12]

The plant is said to contain medicinal alkaloids.^[13]

Acacia stenophylla is widely planted as a drought tolerant and decumbent ornamental tree.^[2] It is cultivated by plant nurseries, and used in modernist gardens and in public landscapes in the Southwestern United States and California.^{[citation needed]}

Acacia stenophylla normally flowers from March to August,^[14] although it can flower irregularly throughout the year.^[6][15] Seed pods turn woody as they mature from October to December and produce approximately 6–12 viable seeds/g.^[7]

Acacia stenophylla seeds germinate prolifically.^[16] Proceeding major floods, seedlings can often be present along the flood-line, but only a very small proportion of these persist.^[10]

Acacia stenophylla belongs to the Genus Acacia, comprising 1200 species worldwide.^[3] 900 of these species are endemic to Australia.^[3]

• Kingdom: Plantae^[3]
• Phylum: Charophyta^[3]
• Class: Equisetopsida^[3]
• Subclass: Magnoliidae^[3]
• Superorder: Rosanae^[3]
• Order: Fabales^[3]
• Family: Fabaceae
• Genus: Acacia^[3]
• Species: Acacia stenophylla^[17]

Common names used in Australia include Balkura, Belalie, Black Wattle, Dalby Myall, Dalby Wattle, Dunthy, Eumong, Gooralee, Gurley, Ironwood, Munumula, Native Willow, River Cooba, River Cooba, and River Myall.^[1]

The specific epithet is derived from the Greek stenos (narrow) and phyllon (leaf) to give “with narrow leaves”.^[18]

•  
  A. stenophylla – Macquarie Marshes
•  
  A. stenophylla – bark
•  
  A. stenophylla – with seed pods (just south of Moree)

• CSIRO Csiro.au: Acacia stenophylla - Australian publication