Coltsfoot

This is arctic sweet coltsfoot, or western coltsfoot - Petasites frigidus var. palmatus a farily widespread species in the sunflower family (Asteraceae). These were growing by the same creek from the last entry, alongside the lone cow parsnip. The two species work well together for this purpose since they're superficially similar, but quite different. Though the coltsfoot flower head is umbel-shaped like the cow parsnip, it's technically a raceme. More-over, its flowers are a world apart, as the plant is in the Asteraceae family. So each "flower" is actually an inflorescence in itself - a composite made of teeny tiny flowers, in this case both "ray flowers" and "disk flowers" just like a sunflower or daisy. And when its seeds become mature, they'll blow away in the wind.

This one hasn't opened yet. I love the purplish color of the involucre (the bracts, or phyllaries, enclosing the inflorescence).

Up close, you can see the disk flowers in the center and ray flowers (they look like petals) on the outside. One of these days I'll get a macro lens...the Canon EOS 50D kit lens (28-135mm IS) isn't too hot in the macro department, unfortunately.

Like the cow parsnip, coltsfoot are insect-pollinated, and their flat-toped flower heads make a nice platform for the insects that come to collect nectar.