Acacia longissima, known colloquially as long-leaf wattle[1] or narrow-leaf wattle,[2] is a species of Acacia native to eastern Australia.
The wattle is slender shrub or small and spreading tree that grows to a height of about . It has dry and membranous stipules that are usually less than in length. Like most species of Acacia it has phyllodes rather than true leaves. The thin and dark green phyllodes have a linear and are usually straight with a length of and a width of with three to seven main veins with the midvein that is most prominent. It blooms between January and May and fruits around November.[2]
The specific epithet is in reference to the long narrow phyllodes of this particular species.[1]
The plant is usually situated near the coast and is found as far north as Nambour and Nerang in south-eastern Queensland extending down the south coastal areas of New South Wales to around Batemans Bay. It is often found to inhabit the borders of rainforests[2] or in wet or dry sclerophyll forest communities where it is often found in gullies growing in sandy to clay soils.[1]