Picea pungens

The Colorado blue spruce or blue spruce is a member of the pine or Pinaceae family and is native to the Rocky Mountains of the United States from the southern border of Montana to New Mexico and Arizona. Its range overlaps quite closely in the United States with Engelmann spruce (P. engelmannii), growing mostly at higher elevations. It grows to 50 m tall.

• Leaves are needle-like, waxy green, 4-sided, sharp, up to 3 cm long, spreading from all sides of the twig. Branches with no needles display short needle stems (sterigmata, or pulvini).
• Pollen cones are red, in whorls of 3–5; seed cones are pendulous, non-fragmenting, pale brown, cylindrical, up to 10 cm long, scales elliptic to diamond-shaped, widest below middle, with wavy, irregular tips. They are quite similar to Engelmann spruce (P. engelmannii) cones.
• Buds are dark orange-brown, 6–12 mm long, apex rounded to acute; bark is gray-brown in colour.
• Blue spruce can be distinguished from Engelmann in having cones up to 10 cm long, (up to 3 cm longer than Engelmann) and needles with a blue tinge, rather than green. However, there is a lot of variation in colour and cone size, and there is interbreeding between the species in the U.S., making distinguishing species sometimes difficult.