Golden wattle is Australia's national floral emblem.  petiolaris H. Vilm. It grows to a height of 8 m (26 ft) and has phyllodes (flattened leaf stalks) instead of true leaves.  The scented flowers have been used for perfume making, and honey production in humid areas. Explorer Thomas Mitchell collected the type specimen, from which George Bentham wrote the species description in 1842. saligna).
His colleague Richard Hind Cambage grew seedlings and reported they had much longer internodes than those of A. pycnantha, and that the phyllodes appeared to have three nectaries rather than the single one of the latter species.
 A. leiophylla has paler phyllodes. Acacia pycnantha generally grows as a small tree to between 3 and 8 m (10 and 30 ft) in height, though trees of up to 12 m (40 ft) high have been reported in Morocco. However, the pollen is too dry to be collected by bees in dry climates. , In 1921 Joseph Maiden described Acacia westonii from the northern and western slopes of Mount Jerrabomberra near Queanbeyan in New South Wales.
In New South Wales it is especially prevalent around Sydney and the Central Coast region.
It grows to a 8 metres tall and has phyllodes instead of leaves. Golden Wattle (Acacia Pycnantha) The golden wattle is the national floral emblem of Australia and is native to southeastern Australia. The ability of an animal or plant species to survive in a particular environment, due to physiological, behavioural or structural changes which are passed down the the next generation. Shiny and dark green, these are between 9 and 15 cm (3 1⁄2 and 6 in) long, 1–3.5 cm (1⁄2–1 1⁄2 in) wide and falcate (sickle-shaped) to oblanceolate in shape. One such adaptation is the poisonous alkaloid that the tree pumps into the leaves. Honeybees, native bees, ants and flies also visit nectaries, but generally do not come into contact with the flowers during this activity. Birds facilitate this and field experiments keeping …  Bentham thought it was related to A. leiophylla, which he described in the same paper.
 As well as being an ornamental plant, it has been used as a windbreak or in controlling erosion. Most carried Acacia pollen but virtually all also carried pollen from other genera.
Self-incompatible, Acacia pycnantha cannot fertilise itself and requires cross-pollination between plants to set seed. , Outside Australia it has become naturalised in South Africa, Tanzania, Italy, Portugal, Sardinia, India, Indonesia and New Zealand. Acacia pycnantha, also known as the golden wattle, is a tree of the family Fabaceae which grow in southeastern Australia.  It is found in the understorey of open eucalypt forests on dry, shallow soils. Acacia westonii Maiden Racosperma pycnanthum(Benth.)
 The type specimen was collected by the explorer Thomas Mitchell in present-day northern Victoria between Pyramid Hill and the Loddon River.
, Like other wattles, Acacia pycnantha fixes nitrogen from the atmosphere. Propagation is relatively easy by normal seed raising methods following pretreatment by soaking in boiling water or by scarification.  Several species of honeyeater, including the white-naped, yellow-faced, New Holland, and occasionally white-plumed and crescent honeyeaters, and Eastern spinebills have been observed foraging.
 In southern Europe, it is one of several species grown for the cut-flower trade and sold as "mimosa".  The larvae of a number of butterfly species feed on the foliage including the fiery jewel, icilius blue, lithocroa blue and wattle blue.  The specific epithet pycnantha is derived from the Greek words pyknos (dense) and anthos (flower), a reference to the dense cluster of flowers that make up the globular inflorescences. Acacia leiophylla Benth.
In Western Australia, it is found in the Darling Range and western wheatbelt as well as Esperance and Kalgoorlie.
 Seeds are able to persist in the soil for more than five years, germinating after fire.