Amellus tridactylus subsp. olivaceus, commonly known in Afrikaans as the vaalastertjie (little grey aster), is a sprawling annual reaching 10 cm to 25 cm in height.
The simple, alternate leaves grow sessile (stalkless) on soft, hairy stems. The oblong leaves rarely have lateral lobes, while the occasional marginal tooth is visible in picture. The margins may be slightly rolled under. The soft grey-green to green blades are channelled and roughly hairy. They become about 2 cm long.
The subspecies distribution is in the Northern Cape and the Western Cape including the Little Karoo. This is the only of the three subspecies that occurs in the Western Cape.
The habitat is diverse lowland vegetation in clay, loam or sandy soils, often in disturbed places and dry riverbeds. The subspecies is not considered to be threatened in its habitat early in the twenty first century (Vlok and Schutte-Vlok, 2015; Manning and Goldblatt, 1997; Bond and Goldblatt, 1984; iNaturalist; http://redlist.sanbi.org).