NATURE NARRATIVES: Cottonwood (pretty shapes)

By Melissa Walker
      

Blue-sky patterns amidst cottonwood branches.
Melissa Walker photos
With this year's warm fall weather, the yellow-gold leaves of the plains cottonwood trees clung to their branches well into November. On a bright, breezy morning, I took a walk on a cottonwood-lined trail that parallels Fountain Creek. Soon enveloped by a huge cottonwood, I paused to look up through its golden, heart-shaped leaves. The tree seemed to capture autumn's blue sky in its upper branches. Then, when the wind blew, the blue-sky pattern would change, reminding me of a kaleidoscope, a wonder-filled toy of my childhood. Later that day, thinking of kaleidoscopes, I decided to find its literal meaning. In Greek, “kaleidoscope” means pretty (kalos) shapes (eidos). Perfect.
       The patterns of leaves against the sky are not the only “pretty shapes” that the cottonwoods create. In his book, “The Thunder Tree,” Robert Michael Pyle describes another unexpected shape:
       “There are stars in the cottonwoods. If you grasp a cottonwood twig, neither too green nor too rotten, and snap it at a wrinkled growth node, a perfect five-pointed star may be revealed on the broken ends. The star is the darker heartwood contrasting with the paler sapwood and new growth.”

Cotton-wood catkins suspended from branches.
Melissa Walker photos

       Earlier this year, in June, I also noticed an unexpected shape when the cottonwoods' developing seeds, called catkins, were hanging from the branches. The reddish-pink catkins looked like jellyfish undulating on waves of air instead of water.
       The huge plains cottonwood are known as the giants of Colorado's lowland rivers. One of the cottonwoods along the trail near Fountain Creek Nature Center measures 22 feet in circumference. The towering trees are in the willow family and grow only where there is a river, stream, spring or water near the surface of the ground. For the first inhabitants and travelers in this part of North America, the sight of cottonwood trees in the distance signaled “Water!” Wood for a fire, shade and drinking water were all available in a cottonwood grove.

Star shapes inside a broken cottonwood twig.
Melissa Walker photos

       Tall cottonwoods provide shelter and food for a wide variety of birds, mammals and other animals along Colorado's low-altitude waterways. In the summer, warblers look for insects among the cottonwoods' highest branches, orioles hang their woven nests in the middle branches, and muskrats burrow under the roots in the streambank. In the fall, migrating hawks perch near the treetops; in the winter, magpies soak up the sun's warming rays on the east-facing branches; and in the spring, owls may nest in the hollows of the tree trunks. Cottonwoods - living kaleidoscopes, full of life.

A Westside naturalist, Walker posts regular entries in her online blog at naturenarratives.com. She has given her permission to reprint selected pieces in the Westside Pioneer.