Taxonomy
- Kingdom: Plantae
- Clade: Angiosperms → Eudicots → Rosids
- Order: Fabales
- Family: Fabaceae
- Subfamily: Mimosoideae
- Genus: Acacia
- Species: Acacia complanata A.Cunn. ex Benth.
Common names
Flat‑stemmed wattle, long‑pod wattle, donkey’s ears.
Description
Acacia complanata is a shrub or small tree endemic to eastern Australia, typically reaching 2–5 m in height, though occasional individuals may grow up to 6 m. The plant is characterised by markedly flattened, winged branchlets that are glabrous and often display a zig‑zag pattern. Its phyllodes (leaf‑like structures) are narrowly elliptic to elliptic, 5–10 cm long and 10–30 mm wide, bright green, with 5–9 prominent longitudinal veins and a reticulate network of minor veins.
Inflorescences are spherical heads of bright yellow flowers, each head containing numerous small florets. Flowering mainly occurs from late spring through autumn, but occasional off‑season flowering has been recorded. The fruit is a linear pod; seeds are attached to a funicle that encircles them, a feature useful in distinguishing the species from related taxa.
Distribution and habitat
The species occurs along the east coast of Australia, from around Bundaberg in Queensland south to near Grafton in New South Wales, extending inland to central Queensland between the Blackdown Tableland and the Alpha‑Tambo region. It favours loamy to gravelly soils on low ridges and is commonly found as an understorey shrub in open forest communities dominated by scribbly gum (Eucalyptus racemosa) or spotted gum (Corymbia citriodora).
Ecology
Acacia complanata possesses a lignotuber, enabling it to resprout after fire or physical disturbance. Its seeds are adapted for fire‑stimulated germination; pre‑treatment by scarification or soaking in boiling water markedly improves germination rates. The species provides nectar and pollen for a range of insects, and its dense foliage offers habitat for small vertebrates.
Cultivation and uses
The plant is valued in horticulture for its ornamental yellow flowerheads and tolerance of a range of soil types. It is suitable for suburban gardens, where it can be pruned to maintain a desired size. Propagation is most commonly achieved from seed after the aforementioned pretreatment; propagation from cuttings is rarely employed. The species is noted for its longevity (often 20 years or more) and low susceptibility to borer attacks.
Conservation status
The species is not listed as threatened on the Australian Government’s EPBC Act list and is considered relatively common within its natural range.
References
- Wikipedia contributors. “Acacia complanata.” Wikipedia, The Free Encyclopedia.
- Australian Native Plants Society (Australia). “Acacia complanata – Flat‑stemmed wattle.”
- Australian Biological Resources Study. “Flora of Australia – Acacia complanata.”
All information presented reflects current, verifiable botanical sources and does not include speculative content.