Acacia octonervia

General Plant Info

Acacia octonervia is a spreading shrub to 1m high, endemic to Australia. It grows in rocky sand, rocky loam or sandy clay, in open mallee, dense low heath and open dwarf scrub, and has light-golden flowers which are present from August to October.

A member of the ‘A. sulcata group’ and most nearly related to Acacia sulcata which has six- or seven-nerved phyllodes, caducous stipules, heads with 10–15 flowers and commonly mottled seeds.

Geographic distribution

Acacia octonervia is distributed in south-west Western Australia, restricted to the area between the Fitzgerald and Young Rivers, with an outlier near Boxwood Hill.

Beard’s Provinces: South-West Province.

IBRA Regions: Esperance Plains, Mallee.

IBRA Subregions: Eastern Mallee, Fitzgerald, Recherche, Western Mallee.

Local Government Areas (LGAs): Esperance, Gnowangerup, Jerramungup, Ravensthorpe.

Identification

Glabrous, spreading shrub 0.1–0.5 (- 1) m, high. Branchlets brownish red, sometimes nitid. Stipules persistent, narrowly triangular, 1.5–2 mm long.

Phyllodes erect, straight or weakly curved, terete, commonly 1–2 cm long, 1–1.5 mm diam., obtuse-mucronulate, rigid, dark green, with 8 distant, raised nerves; stomata raised; gland inconspicuous, 4–10 mm above pulvinus at junction of 2 adaxial nerves.

Inflorescences simple, 1 or 2 per axil; peduncles commonly 7–12 mm long; basal bracts rostriform; heads globular, 3–4 mm diam., 20-flowered, light golden. Flowers 5-merous; sepals free. Flowers Aug - Oct

Pods narrowly oblong, undulate, to 2.5 cm long, 3 mm wide, coriaceous, somewhat nitid.

Seeds longitudinal, ovate or widely elliptic, 2–2.5 mm long, subnitid, brown; aril subterminal.

Cultivation

Grows in sandy clay, gravelly sand or loam.

Links

http://florabase.dpaw.wa.gov.au/browse/profile/13507

http://www.worldwidewattle.com/speciesgallery/octonervia.php?id=13507