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