Picea A.Dietr.
Family: Pinaceae
Picea image
Kitty Kohout  
1a. Young branches finely pubescent; female cones somewhat spherical, 1.5–3 cm long, the scales with erose margins ... P. mariana
1b. Young branches glabrous; female cones cylindrical, 2.5–18 cm long, the scales entire or nearly so... 2
2a. Female cones 2.5-6 cm long; needles spreading, often glaucous; branches spreading ... P. glauca
2b. Female cones 10-18 cm long; needles pointed forward, green; branches pendulous on mature trees... P. abies
Picea pungens Engelm., blue spruce, is a western species that is commonly planted for its blue-green foliage.  It has not been observed to escape in Wisconsin but often persists at old homesteads and farms.  It would key to P. glauca but differs in its needle tips being sharply acuminate and female cones 6–10 cm long, their outer scale margins irregularly toothed.  Spruce needles are borne on prominent peg-like growths on the branches.