Blue spruce
Blue spruce is an evergreen conifer native to the central Rocky Mountains. Its stiff, sharply pointed needles often have a bluish cast.
Picea pungens: Picea pungens is the scientific name of the blue spruce, a conifer in the pine family. This species name identifies the tree classified as blue spruce.
Epicuticular wax: Epicuticular wax is a layer of wax deposited on the outer surface of a plant cuticle. This surface wax scatters light and contributes to blue-gray needle coloration.
Christmas tree: A Christmas tree is a decorated evergreen, commonly a cultivated conifer, used in seasonal celebrations. Blue spruce is grown and sold as a Christmas tree for its form and foliage.
Cytospora canker: Cytospora canker is a fungal disease that causes branch dieback and resinous lesions on stressed spruce trees. It is a major disease of blue spruce, especially in landscapes outside its native climate.
White spruce: White spruce is a North American evergreen conifer with short needles and a broad northern range. It is another native North American spruce, but generally lacks blue spruce’s sharply pointed needles.
Pine family: The pine family, Pinaceae, is a family of conifers that includes pines, spruces, firs, and larches. Blue spruce belongs to this family of cone-bearing trees.
Photosynthesis: Photosynthesis is the process by which plants use light energy to convert carbon dioxide and water into chemical energy. Blue spruce needles capture light and exchange gases for photosynthesis.
Landscape architecture: Landscape architecture is the design of outdoor spaces using landform, plants, water, and built features. Blue spruce is planted as a specimen tree and evergreen screen.
Rhizosphaera needle cast: Rhizosphaera needle cast is a fungal disease that browns and prematurely sheds conifer needles. This disease commonly damages blue spruce foliage in humid conditions.
Engelmann spruce: Engelmann spruce is a high-elevation conifer native to western North America. It shares mountain habitat with blue spruce but has softer, less sharply pointed needles.