Can someone identify this

I just noticed these growths which have sprung up within the last two weeks and some are now three foot tall. At first I thought they were wind borne seed/weeds, as last month our property was covered in two leaf growths which seemed to have appeared overnight and took root and which I weeded out.

However when I looked today, I discovered that they had attached and grown out from around the exposed roots of large Cedar trees and also a few areas on the trunk over 10 foot up, where small branches had broken off on.

I tried to pull off without success and it puzzles what these “parasitical" deciduous broad leaf growths are.

Would appreciate any help with identifying.

 

Don't know what the tree is, but these are just sprouts from that tree and from those roots. Some years you get rather more of them, some less, but these small shoots often don't last. They certainly could, though. I would prune the ones on the roots as close as you can. The sprouts on the tree can often be pulled off when they are this small. Or animals can eat them off.

 

Could they be poplar or cottonwood seedlings ?

 

They look as if they may be cottonwood. This year we had almost cotton wood " snow storms " like never before, where it looked like a layer of snow had fallen on the ground .
Thing that puzzles me is that these " suckers" which look to be deciduous have taken root on evergreen trees which I believe to be Cedar and Fir and only around the exposed root or bark of 5 0r 6 of them in the forest area out of 50 large trees.

 

The seed pods on the ground look to be from poplars or cottonwoods. Maybe ideal conditions for germination where they sprouted this year. It's probably best to keep weeding out those in the ground before they get more established and harder to remove.

 

The tree with the growths appears to have typical Black Cottonwood bark and certainly not Western Red Cedar bark.

 

Populus trichocarpa, stem and root sprouts.

 

Thank you everyone for identifying it as the Poplar Trichocarpra/Back Cottonwood. This is the first time that I have ever seen these sprouts coming from the trees in the forest and I shall remove all sprouts et al forth with.