Agathosma collina, commonly dune buchu and previously A. graveolens, is a dense, single-stemmed, ericoid shrub reaching heights from 1 m to 1,5 m.
The almost stalkless leaves spiral in nearly vertical arrays around the creamy yellow upper stems; the arrays spiral slightly and occasionally become irregular. The leaf-shape is ovate to lanceolate, tapering to acutely pointed tips with entire margins. The upper surface is concave, the blade thickish and somewhat keeled.
Stem-tip leaves are pale yellow-green and slightly in-curving, soon to become green, straight and slightly less ascending. The leaves are mildly aromatic. They become about 4 mm long.
Congested heads of pale yellow-green to white flowers with petals of 4,5 mm long are borne in stem-tip clusters. The thread-like staminodes that are joined to the petal bases are wider in their lower halves. Flowering happens in a long season from before midspring to after midautumn. The ovary and fruit are three-segmented.
The species distribution is coastal between Agulhas and Stilbaai on the Agulhas Plain.
The habitat is stabilised coastal dunes and limestone slopes among fynbos. The species is considered near-threatened in habitat early in the twenty first century due to coastal development and alien plant invasion outside the De Hoop Nature Reserve where it is well established (Manning, 2007; Mustart, et al, 1997; iNaturalist; http://redlist.sanbi.org).