In Bloom: Ode to Fire(weed)
Special to the Aspen Times
I was planning on writing about Fireweed before the Grizzly Creek fire broke out. Because it is a classic, late-summer flower. Because it is having a hay day on Basalt Mountain after the 2018 fire, as well as in the clearings created during the 2019 avalanche cycle. And because, of course, it is a glorious flower.
Now, undoubtedly, it will become a living symbol of death and rebirth in Grizzly Creek.
First, a word about Grizzly Creek. For those who have hiked there, you know that it contains a richness in flora found in few other places in semi-arid Colorado: wood ferns, shooting stars, monkeyflowers. To think of it burning is hard to bear.
That same lushness, though, indicative of abundant water and rich soil, carries the promise of rejuvenation. And Fireweed will be at the forefront of that process.
Fireweed, Chamerion angustifolium, is a native plant that grows head-high and produces dozens of lavish, magenta, four-petaled flowers. Each flower produces as many as 500 seeds, resulting in tens of thousands of seeds per plant. Aided by a tuft of long hairs, each of those seeds can go airborne and establish rapidly.
One of the coolest things I learned about Fireweed from the U.S. Forest Service’s fire studies is that Fireweed seed hairs, or “plumes,” respond to humidity. Increased humidity causes a decreased plume diameter, which results in reduced loft. This increases the chance that seeds get deposited in places with moisture adequate for germination — how smart is that?
By contrast, robustly-plumed seeds can stay airborne for 10 or more hours, allowing the seeds to travel over 100 miles during that time — even smarter!
In case that fails, Fireweed can reproduce not only by pollination, but by rhizomes, underground stems that put out lateral shoots. This is how it reproduces so well following major disturbance events like fires and avalanches. It can even survive volcanic eruptions: one year after the Mount St. Helens explosion, 81% of seeds collected in seed traps were Fireweed seeds.
Maybe, though, one of the loveliest things about fireweed is its modesty; its understanding of the role it plays. Namely, it tends to achieve peak dominance within a limited number of years after a disturbance. In spruce-fir forests like those in our area, Fireweed may be dominant for as long as 10 years after a fire or avalanche, but it will decline in numbers in the face of competing vegetation, and as the forest canopy closes.
In other words, in time Fireweed will recede and allow the wildflowers you’ve grown to know and love in Grizzly, or on Basalt Mountain, or up Conundrum Creek, start to reemerge.
Just one more reason to know and love Fireweed.