Oenethera biennis

Oenothera biennis, usually called the common evening-primrose, is a biennial herb or an annual growing a thick taproot. The plant usually reaches its full height of about 1,6 m in its second year, when it seeds. It is often much shorter during the first year, mainly showing a ground-level leaf rosette.

The lance-shaped leaves are from 8 cm to 18 cm long and from 2 cm to 6 cm wide, produced in a tight rosette during the first year, spiralling up the stem during the second.

Part of the Onagraceae family, this is a native of North America, an exotic weed in South Africa. The plant has become established on all continents except Antarctica. The photo was taken near Hermanus.

The habitat is loamy soil at elevations below 700 m above sea level.

The species resembles O. stricta, another weedy, yellow-flowering escape in South Africa.

Evening-primrose oil is derived from the plant. It also featured in traditional medicine and as food (iNaturalist; Wikipedia).