Oxalis luteola

Oxalis luteola, commonly yellow sorrel or sometimes golden sorrel and in Afrikaans sandsuring (sand sorrel) or pienk suring (pink sorrel), is a stemless, hairy perennial, a dwarf herb reaching heights from 5 cm to 8 cm when the flowers are present.

The radical leaves forming the basal rosette grow on petioles up to 4 cm long. Each leaf consists of three broadly wedge-shaped, stalkless leaflets that are conspicuously veined below. The sometimes hairy blades are shallowly indented near their tips, often purple on the lower surfaces and along the sometimes in-curving, entire margins. The upper surfaces of the leaflets may be green or dark reddish, the colouring clues for the pienk suring name.

The bright yellow flowers grow solitary on articulated pedicels with opposite bracts at the joints. The five round- to square-tipped petal lobes spread. There are dark vein lines from the lower blade parts in picture into the funnel-shaped cup. Some plants are orange inside the corolla cups of their flowers.

There are ten stamens showing ten yellow anthers in two series in the flower mouth, five of them on shorter filaments. There are also five styles on the five-locular ovary, not visible in the photo.

The specific name is derived from the Latin word luteus meaning deep yellow or golden yellow and the word part -olus which indicates the diminutive form, referring to the flower colour and the plant smallness. O. flava is also yellow, flavus being another Latin word meaning yellow.

Flowering happens late in autumn or early in winter.

When flowering is over, the pedicels become inclined, arching their tips down near the ground where the fruits develop.

The species distribution is in the southwest of the Western Cape, from Clanwilliam and Tulbagh to the Cape Peninsula and eastwards to Riversdale. The photo was taken at the Hermanus golf course.

The habitat is sandy flats and lower fynbos slopes, coastal and inland. The species is not considered threatened in habitat early in the twenty first century (Manning, 2007; Bean and Johns, 2005; Leistner, (Ed.), 2000; Bond and Goldblatt, 1984; Andrew, 2017; iNaturalist; http://redlist.sanbi.org).