Pelargonium luteolum is a perennial that grows from a tuberous rootstock. It resprouts after fire, reaching heights around 20 cm when in flower.
The inflorescence is a many-flowered umbel on a long, sometimes branched peduncle. The calyx tube ranges from 15 mm to 25 mm in length, individual flower pedicels short.
The upper petal pairs in picture are close together or overlapping, the central one of the lower three bigger. It is often the lower petals that overlap and obscure the stamens and style from view. The flowers are pale yellow, rarely pink, luteolum confirming the yellow.
All petal bases are usually marked in dark red purple, the lines low down on the lobes about parallel, sometimes with feathery embellishments. The markings on the upper petal pair are often bigger. Flowering happens from before midsummer to autumn.
The species is found in the Western Cape, mostly from Worcester to the Little Karoo and Mossel Bay but also in Namaqualand into the Northern Cape and to Steytlerville in the Eastern Cape. The photo was taken at Minwater near Oudtshoorn.
The habitat is succulent Karoo, variable karoid scrub and renosterveld, the soils sandy or clayey. The species is not considered threatened in habitat early in the twenty first century (Vlok and Schutte-Vlok, 2015; Bond and Goldblatt, 1984; iNaturalist; http://redlist.sanbi.org).