Landscape: Rhizosphaera Needle Cast Center for Agriculture, Food, and the Environment at UMass Amherst
The giants of Cornell - Cornell College
Colorado's Major Tree Species, Colorado State Forest Service
Landscaping Guide for Colorado Blue Spruce, Blog
Spruce, Colorado (Blue) Nebraska Forest Service
Blue Spruce - Bryce Canyon National Park (U.S. National Park Service)
About the Colorado Blue Spruce, Colorado Blue Spruce, a relaxed evergreen tree that is indigenous to the Rocky Mountains. Its striking blue-green
Colorado Blue Spruce
Picea pungens, Colorado spruce
upload.wikimedia.org/wikipedia/commons/1/11/Picea_
Basic Tree, Tree Identification, Regional and Community Forestry, School of Natural Resources
Rhizosphaera Needle Cast of Spruce