Acacia longifolia subsp. sophorae is a generally a prostrate shrub when growing on exposed coastal dunes, but may grow as a large shrub to 2-3 metres in height (sometimes taller) in more sheltered locations such as near-coastal forests. It grows purely close to the coast, from south-east Queensland to South Australia, including Tasmania, usually on sand dunes. Has become a weed in western Victoria and SA.
Currently, it is treated as a subspecies of Acacia longifolia in NSW, which is usually a much taller plant with more elongated phyllodes. But is considered a separate species by other botanists.
The phyllodes (modified leaves) are elliptic to obovate, to 11 cm long and to 3 cm wide with prominent longitudinal veins.
The bright yellow flowers are produced in linear spikes, to about 5 cm long and about 0.6 cm wide, occurring in the axils of the phyllodes (1 or 2 per axil). Flowering is mainly in late winter and spring.
Seed pods often coiled and twisted on opening.
It is hardy in a wide range of habitats and soil types provided they are not waterlogged. A position in full sun or light shade is suitable and the species is tolerant of at least moderate frosts. Suitable for coastal plantings. Can make a solid ground cover if the form obtained is prostrate.
A. longifolia subsp. sophorae has become an environmental weed in some areas (eg. western Victoria and South Australia).
Care should be exercised in planting these species in areas close to bushland.
Acacias can suffer from a number of pests, including borers, scale, galls and leaf miners. Growing plants suitable to your local environment minimises these occurring.
Propagation is easy from scarified seed by covering with boiling water for 24 hours and discarding any seeds still floating on the surface.
Most wattles regenerate from seed after fire, with some species exhibiting suckering from the basal areas.
Acacia – from Greek acis, meaning a thorn or “thorny”.
sophorae – similar to some species in the genus Sophora – a genus of peas which are spread worldwide.