Trees associated with Colorado (6)

I believe the answer is:

aspens

(Other definitions for aspens that I've seen before include "Kind of poplars with shivering leaves" , "Trees that shiver, kind of poplars" , "Species of poplars with leaves that quiver" , "Poplar trees that shiver in the wind" , "Trees with leaves that quiver" .)

I've seen this clue in the Newsday.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.