Cottonwood pods preparing to broadcast seeds on cotton fluff.

Cotton collected on a Grand Mesa trail

Cottonwoods are notorious for spewing cotton each spring, but the trails my husband and I followed on Colorado’s Grand Mesa were far from cottonwood country. So why was cotton everywhere? We were surrounded by aspens and spruce, and as far as we knew, neither produced cotton. Spruce trees launch their seeds in cones. Why would they make cotton? Suspicious. I scrutinized grove after grove and finally spotted fluffy tufts wafting off an aspen treetop.

More Grand Mesa cotton

I’m a fifth-generation Colorado native who’s spent considerable time in the mountains. I’ve also watched three aspen clusters in our yard for over 35 years, so how did I miss this cotton production trait for over half a century?
As it turns out, aspens are rife with secrets. I’ve often read that aspen groves stem from a single root system so are considered one organism rather than a grouping of individual trees, but I didn’t know that the aspen’s lifespan is phenomenal. Utah’s Fishlake National Forest hosts the oldest known aspen grove…which is also the oldest known organism of any kind—80,000 years!
I once followed a hiking guide who disparaged aspens as being “trash trees” because they are generally short-lived. When I shared that assessment with a friend, she quoted another guide who’d called aspens “soda straws” because they are full of water. They’re prized fire suppressors protecting their more flammable conifer neighbors. 
Another unexpected nugget I discovered is that the aspen’s white bark hides a green photosynthetic layer which continues producing sugar through the leafless winter. Deer and elk use these calories cached beneath the tender bark to survive harsh winters.
The mention of tender bark revives a mystery I happened on a while back. Ugly scars on the aspens along a ranch’s access track made me wonder what happened to them. The rancher explained that elk rub their antlers against the bark. The U.S. Fish and Wildlife Service website confirms that deer and elk rub their antlers on tree trunks to rid themselves of velvet which is also interesting stuff but beside my point that the animals might be eating the bark as well.
One final humiliation before I quit: I’ve always considered aspens to be exclusive to the American West.

Trying, but not quite one with nature….

Wrong again. Some aspens are easterners. They’re also found in Europe, Asia, and Africa. Coloradans may be blessed, but we sure don’t know it all.