Abies lasiocarpasubalpine fir

• Needle single, flat in cross-section

• Twigs not roughened with sterigmata

• Cones erect• Needle same width

where it attaches to stem as in the middle

• Needles attach like suction cups (circular leaf scar)

Alnus tenuifoliaalder

• Strobili with persistent woody bracts

• Leaves strongly doubly serrate

• Smooth stems and bark

Betula occidentaliswater birch

• Leaves irregularly serrate• Rough twigs and bark• Riparian

Juniperus scopulorumRocky Mountain juniper

• Needles scale-like, appressed, opposite, four ranked

• Small tree• Berry-like cone

Picea engelmanniiEngelmann spruce

• Needle single, 4 angled in cross section, not sharp to touch

• Sterigmata present• Old bark cinnamon-

orange, thin and scaly• Cones less than 6 cm

long• Twigs with "peach

fuzz" (hairy)

Picea pungensblue spruce

• Needles 4 angled in cross section, sharp to touch

• Sterigmata present• Old bark grayish,

longitudinal ridges• Cones greater than 6 cm

long• Twigs glabrous

Pinus contortalodgepole pine

• Needles 3-7 cm, in fascicles of 2

• Old bark thin and scaly

• Some closed cones (serotinous), persistent in tree

• Small cones

Pinus flexilislimber pine

• Needles in fascicles of 5

• Stems very limber• Needles clustered at

tip• Cones resinous with

thick scales

Pinus ponderosaponderosa pine

• Needles usually longer than 7 cm, in fascicles of 2 or 3

• Old bark thick with deep furrows, smells like cream soda

• Cones open, falling from tree, armed with a sharp prickle

Populus angustifolianarrowleaf cottonwood

• Leaves lanceolate• Buds terminal with

overlapping scales• Catkins drooping

Populus tremuloidesquaking aspen

• Petiole flattened perpendicular to the plane of the leaf

• Leaves nearly circular• Buds with overlapping

scales• Catkins drooping

Prunus virginianachokecherry

• Simple leaves, serrate margins with teeth pointing toward the tip of the leaf

• Two glands at base of petiole

Pseudotsuga menziesiiDouglas-fir

• Needles with a petiole-like constriction at base

• Cones with large, three-pointed, exerted bract

• Buds dark reddish brown, pointed