Which of the following is known as Noble Fir?

The correct answer is the species Abies procera, commonly known as Noble Fir. This tree is a native conifer to the Pacific Northwest and is recognized for its tall, straight growth habit, dense conical shape, and attractive blue-green needles that have a soft appearance. Noble Fir is also valued for its strong and straight timber, making it a popular choice for Christmas trees and for use in construction.

In contrast, the other species listed do not correspond to the common name "Noble Fir." Calocedrus decurrens, also known as Incense Cedar, is characterized by its fragrant wood and scale-like leaves, distinct from the needle-like leaves of firs. Cedrus atlantica 'Glauca,' or Blue Atlas Cedar, belongs to the cedar family and has a different growth habit and foliage coloration. Cedrus deodara, known as Deodar Cedar, is a large evergreen tree native to the western Himalayas and displays a different form and leaf structure as well. Understanding these differences helps identify the various conifers and their specific characteristics.