Picea engelmannii forest (Engelmann Spruce)
Pinaceae (Pine Family)

Montane, subalpine, alpine. Woodlands. Spring.

Charles Parry collected Picea engelmannii in Colorado and named it to honor his friend and botanical colleague, George Engelmann, St. Louis physician, botanist, and Colorado plant collector whose collection formed the nucleus of the now world-famous Missouri Botanical Gardens in St. Louis. Engelmann published Parry's description of this tree in 1863. (He published his own description of Picea pungens (Colorado Blue Spruce) in 1879.) 

"Picea" is derived from the Latin "pix", or "picis", meaning "pitch", and is the classical Latin name for a now unknown Pine.