Zephyranthes  

These bulbs come in various shades of white, yellow, pink and rose. They are called rain lilies as they have a tendancy to bust into flower after rain in Summer/Autumn. In cultivation the rain lily will flower throughout the year if kept alternatively wet and dry with the majority of blooms in Summer and Autumn. The narrow, grass like foliage blends in well in rock gardens and can be used as borders in gardens and containers. These small perennials are among the easiest bulbs to grow and if left undisturbed will develop over several seasons into truly impressive clumps. 

They prefer a warm to hot climate and grow best in morning sun. In cooler areas it may need some protection (eg mulch over Winter). They like a moist soil so water regularly in dry periods but once established can tolerate dry periods.  The best way to grow  Zephyranthes is from bulbs as seed grown plants will not flower for 3 to 4 years.