Isopogon dawsonii, commonly known as the Nepean conebush,[1] is a shrub of the family Proteaceae and is endemic eastern to New South Wales. It has pinnate leaves with narrow segments and spherical heads of creamy yellow to greyish white flowers.
Isopogon dawsonii grows as an upright shrub, its height usually ranging between but can grow to . The branches are reddish brown, the branchlets and leaves covered with greyish hairs when young. The leaves are pinnate, long on a petiole up to long, with segments wide. The flowers are arranged in more or less spherical, sessile heads long in diameter with overlapping egg-shaped involucral bracts at the base. The flowers are long, creamy yellow to greyish white and densely hairy. Flowering occurs in spring and the fruit is a hairy oval nut long, fused with others in a spherical cone in diameter.[2] [3]
Isopogon dawsonii was first formally described in 1895 by R.T. Baker in Proceedings of the Linnean Society of New South Wales from an unpublished manuscript by Ferdinand von Mueller.[4] [5] The specific epithet (dawsonii) honours James Dawson of Rylstone.
Nepean conebush occurs naturally on sandstone slopes and near cliff edges in heathland and dry sclerophyll forest in the valleys of the Goulburn and Nepean Rivers, on the Central Coast, the Central Tablelands and the Western Slopes down to Lithgow.
This isopogon can be grown from seed or from cuttings of firm new growth. It will grow in a range of conditions and is drought and frost hardy. It has been used as rootstock for some Western Australian species of isopogon.