Mutualism in Nature, part 2

I talked last week about flowers and their pollinating partners, how different plants have developed strategies to lure in certain pollinators. Strategies like fragrance and color.

But not all fragrance smells like a rose. Skunk cabbage, named for its smell, lures in flies and beetles that think they've found something good and rotten. The lovely red trillium, another early bloomer, employs a stinky smell plus a blood-red color for further effect.

Some wildflowers evolve to attract a specific pollinator, and there’s no better example than cardinal flowers and hummingbirds. In August, clusters of iridescent red cardinal flowers bloom along New Hampshire waterways. Many tubular flowers grow on each upright stem.

Hummingbirds are attracted to red, and have evolved to sip nectar from these flowers. They also feed most actively in August, doubling their weight before they take off for their long journey south. It’s no coincidence that cardinal flower blooms in August.

Hummingbirds work a cluster of these neon red blooms in a blur of speed. But, in slow motion, here's what's going on. The hummingbird hovers, tongue extending to reach nectar deep within the flower tube. Inadvertently, its forehead touches another tube that bears pollen. With pollen on forehead, the hummer moves on to sip at a female flower whose pollen receptor is located in just the right place with just the right stickiness. And transfer of pollen from forehead to flower is achieved.

In time, pollinated flower develops seeds and well fed hummingbird departs on migration. But right now, cardinal flowers and hummingbirds can be observed – down by the riverside:
A great place to spend some time before summer slips away.