Pelargonium hirtum is a branched shrublet with stems that are a little succulent, but also woody. It is summer deciduous, growing in winter.
The leaves are hairy, finely divided on long petioles and crowded at branch ends. They are soft to the touch, giving the plant a bushy appearance when lush in winter. The leaves resemble fern or carrot leaves, giving rise to the Afrikaans name of wortelblaarmalva.
Flowers appear in winter and spring on long, thin, hairy stalks that also carry clusters of smaller leaves. The flowers grow in clusters of up to five. Their colour is shades of lavender pink or rose to almost white, with rounded petals. The upper petal pair have dark pink markings and bigger than the lower three.
The species distribution is from the Cape Peninsula to Saldanha and Stellenbosch in sandy soil among rocks (www.darwin.bio.uci.edu; Bond and Goldblatt, 1984; Manning and Goldblatt, 1996).