Oxalis truncatula lower surface of leaf

Seen from below, this Oxalis truncatula leaflets are red and covered in long, pale brown or rust-coloured hairs. The plant may, however, also have green lower leaflet surfaces, the red colouring not much use in identification of the species. Still, a common name of purple hairy-back sorrel is on record.

Truncatula (Latin) means small and truncate, as if cut straight across. The midrib and major veins are raised below, sunken above.

O. truncatula is a stemless perennial growing lilac flowers with pale yellow centres; some fine lines from the centre spread along the petal surfaces. Two small opposite bracts occur on the flower stalks (Bean and Burman, 1985; Bond and Goldblatt, 1984; iSpot; Andrew, 2012).