The genera Brodiaea, Dichelostemma and Triteleia, from western North America, have kept the botanists busy for many years, and lots of plants have been placed in several different genera. The differences are rather technical, but Dichelostemma have denser umbels of flowers. They are all pretty bulbs (corms), easy to grow in sunny, well-drained places, producing their heads of many starry flowers in summer. They are good growing through low ground-covering plants.