A commonly held belief is that in order to be cross-pollinated, flowers have evolved to attract certain pollinators, including wind, mammals, birds and insects. These traits, or “pollination syndromes,” include the flower shape, color, odor, amount of nectar and flowering time. Flowers attractive to hummingbirds tend to be large, tubular-shaped and colored red, orange (or sometimes yellow). These flowers usually have a large supply of dilute nectar, which they secrete during the day. Since birds do not have a strong response to scent, the flowers they visit tend to be odorless.
Canada Lilies, found throughout eastern North America, have a distinct tubular shape, which appeals to Ruby-throated Hummingbirds. Their long, thin beak allows these birds to reach nectar at the base of the flower that is inaccessible to many other creatures. In order to reach the nectar, the hummingbird must enter the flower far enough so that its neck and breast press up against the orange pollen-laden anthers of the Canada Lily. When the hummingbird moves on to the next Canada Lily flower, it is very likely that some of this pollen will end up on the flower’s female structure, or stigma, thereby pollinating the flower. (Note that the stigma, in the center of the flower, is taller than the anthers, thereby discouraging self-pollination.)