Where I a few years ago planted a native columbine, Aquilegia formosa, which has red, relatively short-spurred petals, this form now grows. I don’t think it has evolved; I think seed from a horticultural variety from elsewhere in the garden landed here and my original plant perished over the winter. But it’s worth mentioning that the presence of spurred flowers does seem to speed up evolution within groups of flowers, both in terms of morphological change and speciation. The spurs are hollow, with stores of nectar at the closed ends. Pollinators such as hummingbirds, bumblebees and sphinx moths extend their tongues to obtain the nectar and in doing so contact the pollen-laden anthers. Pollen is carried to the stigma of subsequent plants visited.
Different species of columbine have differently-sized and differently-shaped floral spurs. It has been hypothesized that these are specializations that have evolved to attract specific pollinators, bird or bug, or type of bug. Certain pollinators would visit, thus pollinate, columbines whose nectar tubes best fit their schnozz - or rather the length of their tongue. In this way certain nectar tube morphologies would be selected for, and reproductive isolation among different forms would result -- and voila -- speciation. The spurred columbine form is believed to have evolved multiple times from un-spurred ancestors.
And then there’s this, a columbine conspicuously not from nature, but from a horticulturalist. The previous flower is also not entirely a product of nature, was selectively bred for its colour, but at least it retains a more or less natural form. This second, spurless flower is a sport, a freaky thing, like a Pomeranian. I think it’s sterile, but am not entirely sure.
If you were bug or bird, you wouldn’t know where to stick your nose.
Columbines—Elegant Flowers Spurred to Greatness. Katherine Gould. Plants & Gardens News Volume 16, Number 1. Spring 2001.
National Science Foundation (2007, June 8). Columbine Flowers Develop Long Nectar Spurs In Response To Pollinators. ScienceDaily. Retrieved May 21, 2008