Romulea is a genus in the Iridaceae family of about 90 species that is found both in South Africa and in Europe. Rootstock is a corm, globose, bell shaped to top shaped, compressed or asymmetric with a circular to crescent shaped basal ridge. This genus has flowers reminiscent of Crocus. Many are quite striking, especially the South African species and there is a great variation in colour and markings of the flowers. They are easy to grow in pots and many are easy from seed, flowering rather quickly in some cases.

Romulea vinacea, commonly known as Froetang or Knikker, is a rare range-restricted South African endemic species found in the Northern Cape and Western Cape provinces from Pakhuis Pass to Oorlogskloof growing amongst fynbos in sandy soils on upper plateaus. From late winter to spring it has pale blue violet flowers opening only for a few hours late in the day. The flowers are marked with violet veins and sometimes violet blotches in the throat. The outer tepals are shiny and plum or wine coloured on the back.