Acacia derwentiana

Acacia derwentiana, known as Derwent cascade, is a shrub belonging to the genus Acacia and the subgenus Juliflorae that is native to Tasmania.

Description
The shrub typically grows to a height of 1 to 3 m but can be as tall as 5 m. It has slender branchlets that are arching or pendulous at the extremities. Like most species of Acacia it has phyllodes rather than true leaves. The flat, evergreen phyllodes are scattered with a linear to narrowly elliptic shape with a length of 2 to 6.5 cm and a width of 1 to 2.5 mm. The phyllodes are pungent and have three nerves, the middle one being the most prominent. When it blooms it produces simple inflorescences with interrupted cylindrical flower-spikes that have a length of 10 to 25 mm containing pale yellow to almost lemon yellow coloured flowers. After flowering seed podd form that are linear to curved and irregularly constricted between each seed. The pods are 2.5 to 5 cm in length and 2 to 4 mm wide and contain elliptic shaped seeds.

Taxonomy
It is closely related to Acacia riceana but the phyllodes are more elongated.

Distribution
It is endemic to southern parts of Tasmania where it is mostly situated along the banks of the Derwent River and a few of its lower tributaries including the Broad and Tyenna Rivers. It is also found along the Carlton River and Prosser Rivers and their tributaries also to the north and east of Hobart.