Acacia blakei subsp. diphylla, Gorge Wattle
Acacia blakei subsp. diphylla is known as the Gorge Wattle. This common name refers to one of the species’ strongholds in the gorge country, east of Armidale in northern NSW. The other major occurrence is towards the coast along Thunderbolts Way near Gloucester, NSW. There are also populations in southeast Queensland.
Acacia blakei subsp. diphylla is a tall, upright tree that may reach a height of 15 metres. Bark is fissured and grey. The species is unusual in having both juvenile and adult phyllodes. Adult phyllodes are up to 17 centimetres long and leathery whilst the juvenile phyllodes are the same size but are soft and shiny. In both cases foliage is dense.
In mid spring plants become covered with golden yellow, rod-shaped flower heads. Both foliage and flowers are attractive features.
The Gorge Wattle could be cultivated as a “stand alone” specimen in the larger garden. It could also be cultivated as an eye-catching component of shelterbelts and windbreaks.
Acacia blakei subsp. diphylla is one wattle that does not require pruning to maintain its shape and foliage density. There are a number of specimens, at least 15 years old, in our cold climate garden that have never been pruned.
Propagate from seed that should be soaked in boiling water before sowing. The species may also be propagated from cuttings.
The species was originally named Acacia diphylla but in 1990 was made a subspecies of A. blakei, as the latter species does not have immature phyllodes. Perhaps the name A. diphylla should be reinstated because this is a major species difference.
Warren and Gloria Sheather