Engelmann spruce vs Engelmann's spruce

Engelmann spruce and Engelmann's spruce both are nouns.

Word	Noun	Adjective	Verb	Adverb
Engelmann spruce	Yes	No	No	No
Engelmann's spruce	Yes	No	No	No

As nouns, Engelmann spruce and Engelmann's spruce are synonyms defined as:

Engelmann spruce and Engelmann's spruce: tall spruce of Rocky Mountains and British Columbia with blue-green needles and acutely conic crown; wood used for rough lumber and boxes

Other synonyms of Engelmann spruce include Picea engelmannii.

Engelmann spruce (noun)	Engelmann's spruce (noun)
tall spruce of Rocky Mountains and British Columbia with blue-green needles and acutely conic crown; wood used for rough lumber and boxes	tall spruce of Rocky Mountains and British Columbia with blue-green needles and acutely conic crown; wood used for rough lumber and boxes