Cottonwood cotton is a collection of fine hairs that help seeds fly with the wind and float down the river. This is good for seed dispersal but can cause problems for humans. At peak season female trees produce masses of fluff, which Russians call “pukh”. Pukh reaches hazardous proportions in Moscow every summer; some blame Krushchev, others Lenin (read more here and here). In any case, landscapers now know better than to plant female trees in town.
By June 22, many of the lanceleaf cottonwoods along the Laramie River were releasing seeds, but not mine. I wasn’t surprised. After all, she was a late bloomer back in May.
|Looking up at the cottony canopy of a cottonwood tree (not mine); click on image to view.|
|Female catkin with seeds ready to fly.|
You may remember from my mid-May report that the flooded river submerged benches and left my tree stranded on an island. The water started dropping in mid-June. Soon my tree was accessible, but with all the mud and debris and decaying matter, the area was a bit stinky. And mosquitos were out in force. June visits were short.
|My cottonwood on left; Rich's bench on right (it was completely underwater a month ago).|
Mud records those who passed: birds, raccoons, dogs, people and bicycles.
I took female catkins of various ages back to the house for portraits.
|Plump capsules filled with seeds and cotton.|
|Several capsules starting to dehisce (botany-speak for "split open").|
|Cottonwood seeds are tiny, dwarfed by the cotton. They're made to travel.|
On June 29, I walked to the river early in the morning, while the mosquitos were still asleep. I found the path littered with female catkins. There were patches of pukh scattered about, though nothing like the fluff that plagues Moscow.
|Female catkins on path, with pukh accumulations along right edge.|
Wild Alyssum covered in pukh ... and it’s not even her own!
I crossed the footbridge and visited my tree -- she was casting seeds to the wind.
I took many many many photos before I finally caught some seeds flying away. Then I discovered that making a movie of them was a whole lot easier!
|Tree-following is kindly hosted by Lucy Corrander of Loose and Leafy.|