The rainbow shower is an example of a natural hybrid which occurred in a garden in hawaii, where there are no native cassia species, between the golden shower tree (cassia fistula) and apple blossom cassia (cassia javanica). The hybrid was so attractive that additional plants were produced by intentional cross-breeding. This hybrid produces very few seeds and hence is propagated by grafting or air layering. Rainbow shower tree resembles in appearance, growth requirements and landscape use of its parent species, described in other entries, but is more desirable as an ornamental because it has more abundant flowers which last longer, produces variably colored blooms with shades of white, yellow, pink, orange and red, and produces few if any pods, reducing the litter problem. Rainbow shower is the most common street tree in honolulu and has been designed that city's official tree. It is a good choice for gardens or parks as a showy accent or specimen tree.