Oenothera sp

The species vary in size from small alpine plants 10 cm tall, to vigorous lowland species growing to 3 m. The leaves form a basal rosette at ground level and spiral up to the flowering stems; the leaves are dentate or deeply lobed. The flowers of many species open within less than a minute in the evening, hence the name "evening-primrose", and are yellow in most species but white, purple, pink or red in a few