Merwilla, placed in the Hyacinthaceae family, are perennial bulbs with narrow basal leaves and erect stems bearing racemes of star-shaped, flat or bell-shaped flowers which are often blue.

Merwilla plumbea, synonymously known as Scilla natalensis and commonly known as Blousalngkop in Afrikaans and Blue Squill or Blue Hyacinth in English, is a South African indigenous attractive bulbous plant with its papery bulb scales often visible above the ground. The leaves are relatively short and broad and have distinct veins on them. Attractive clusters of small, blue flowers are produced on robust stalks in spring. Merwilla plumbea is an important traditional medicine and may cause injury or perhaps even death if not used correctly. All parts of this medicinal plant plant contains the cardiac glycoside bufadienolide.