I've grown it. It's an annual native to the southwestern US, and hummers adore it. There are several varieties available, 'Lady in Red' being one. Another that I really like is called 'Forest Fire', with those intense red tubular blooms held in dark, almost black calyxes on a black stem. The red/black contrast is striking and very attractive. This variety is a little shorter and denser growing than 'Lady in Red'.

There are white and peachy-toned cultivars, too. The hummers like the red ones best, of course. The species is easy to grow from seed, and I've had it reseed itself on occasion. The plants are often available in 6-packs at garden centers this time of year.