This is a genus of small, bulbous plants, which produce masses of star-shaped flowers in late winter and early spring. These are usually in shades of blue, purple or white, but pink and yellow forms are sometimes found. The leaves and bulbs smell strongly of onions when crushed, but the flowers are sweetly scented.
There are just 10 species, but few are common in gardens. They originate almost entirely from Argentina and Uruguay.
They grow best in a sunny spot, with well-drained soil, but will tolerate light shade. They dislike winter wet and disturbance of clumps should be kept to a minimum.