1.a. Stems woody ... 2. Trees
1.b. Stems herbaceous ... 21. Herbaceous Plants
2. Trees
2.a. Leaves Scale-like ... 3.
3.a. Twigs Flat ... Thuja plicata (Western Redcedar)
3.b. Twigs Round ... Chamaecyparis nootkatensis (Yellow Cedar)
2.b. Leaves Needle-like ... 4.
4.a. Needles in Clusters ... 5.
5.a. Needles in Clusters of 2 ... Pinus contorta (Shore Pine)
5.a. Needles in Clusters of 5 ... Pinus monticola (Western White Pine)
4.b. Needles Not in Clusters ... 6.
6.a. Needles with No Stalks ... Abies grandis (Grand Fir)
6.b. Needles with Stalks ... 7.
7.a. Stalks fall with Needles, cones with 3-prong bract ... Pseudotsuga menziesii (Douglas-fir)
7.b. Stalks remain after Needle fall ... 8.
8.a. Needles 4-sided, stiff, sharp points ... Picea sitchensis (Sitka Spruce)
8.b. Needles 2-sided ... 9.
9.a. Needles equal length, alternate, sharp points ... Taxus brevifolia (Western Yew)
9.b. Needles different length, opposite/spiral, blunt ... 10.
10.a. Needles Flat, 2 rows, green above, 2 white bands below, cones 2-3cm ... Tsuga heterophylla (Western Hemlock)
10.b. Needles half-round, keeled beneath, crowded, white bands both surfaces ... Tsuga mertensiana (Mountain Hemlock)
2.c. Leaves Broad ... 11.
11.a. Bark peels ... 12.
12.a. Leaves Evergreen ... Arbutus menziesii (Arbutus)
12.b. Leaves Deciduous ... Betula papyrifera (Paper Birch)
11.b. Bark does Not peel ... 13.
13.a. Fruit like apples ... 14.
14.a. Thorns ... Crataegus (Hawthorne)
14.b. No Thorns ... Malus fusca (Pacific Crab Apple)
13.a. Fruit Not like apples ... 15.
15.a. Leaves Compound Leaflets ... Fraximus latifolia (Oregon Ash)
15.b. Leaves Simple ... 16.
16.b. Leaves Lobed ... 17.
17.a. Leaves Opposite, maple-like, 2-winged fruit ... Acer macrophylum (Bigleaf Maple)
17.b. Leaves Alternate, oak-like, acorn fruit ... Quercus garryana (Garry Oak)
16.b. Leaves Not Lobed ... 18.
18.a. Leaves Opposite, smooth margin ... Cornus nuttallii (Western Flowering Dogwood)
18.b. Leaves Alternate, toothed margin ... 19.
19.a. Leaves Double-toothed margin, Fruit cone-like catking ... Alnus rubra (Red Alder)
19.b. Leaves Single-toothed margin ... 20.
20.a. Flowers Inconspicuous in Catkins, Hairy Tufted Seeds, Bark Furrowed Without Lenticels ... Populus balsamifera spp. trichocarpa (Black Cottonwood Poplar)
20.b. Flowers Showy, Fragrant; Fruit Fleshy Cherries; Bark Smooth With Lenticels ... Prunus emarginata (Bitter Cherry)
21. Herbaceous Plants
21.a. Herbaceous Leaves Opposite ...
21.b. Herbaceous Leaves Alternate ...
21.b.1. English Ivy Hedera helix ...
21.c. Herbaceous Leaves Whorled ...
21.d. Herbaceous Leaves Compound ...
21.d.1. Dull Oregon Grape Mahonia nervosa ...