A great reference book is available from UBC Press is:
Indicator Plants of Coastal British Columbia K. Klinka, Krajina, Ceska & Scagel 1989 (re-printed 1995)

Trees
Grand fir grows to a nice height

Shrubs
Twinflower also makes a good ground cover but needs other trees overhanging to keep some moisture close.
False boxwood loves shade and does well where it's dry. It's fairly low-growing shrub.
Oregon grape does extremely well in shade and dry once established. Salal provides evergreen leaves and mealy berries.
Red huckleberry has urn-shaped flowers for bees and butterflies and red berries Trailing Blackberry

Herbaceous plants
Rattlesnake plantain has variegated leaves for year round color.
Piggy-back plant does best under overhang of other trees to keep it moist
Yerba Beuna, which can grow to be a good ground cover, the bonus is you can also use the leaves to make a fragrant tea.
Fringecup has delicate flowers with a bright green rosette of leaves.
Fawn lily: mottled leaves last until mid-summer and of course the curled white flowers are great in april and early may.
Vanilla leaf AKA Elephant Ears unique leaf-shape that will carpet the Ground.
Bleeding heart will carpet the ground
Self-heal or Heal-all blue/purple flowers occur in June.
Red columbine flowers in June and attracts butterflies and hummingbirds.
Oregon beaked moss grows quickly to create a green carpet on logs, stumps or soil.
Step moss adds a thick brown-green mat on the ground and logs.
Sword fern (must have a thick layer of duff).
Licorice fern prefers to grow hanging on rocks and stumps with heavy moss/bark mulch layers.

Shrubs
Flowering red current attract the hummers and is early spring-march to early april flower.
Orange honeysuckle has trumpet-shaped flowers that last all summer and red berries.
Saskatoon has white flowers and blue berries that can be eaten fresh.
Oceanspray has white cascades of flowers in June.
Common snowberry provides white berries all winter for the birds.
Bearberry or Kinniknick provides orange berries for the birds in Winter.
Flowering dogwood provides showy white flowers in june and berries in the fall.
Douglas maple has maple seeds that provide food for birds.
Indian Plum is the first native shrub to flower in March. Flowers change to small purple plums for the birds by the end of June.
Beaked Hazelnut provides leafy cover and nuts for birds and squirrels.
Cascara

Herbaceous
Small-flowered alumroot can tolerate dappled light.
Rattlesnake plantain has varigated leaves for year round color.
Yerba Beuna, which can grow to be a good ground cover, the bonus is you can also use the leaves to make a fragrant tea.
Fawn lily: mottled leaves last until mid-summer and of course the white flowers are great in april and early May.
Chocolate lily flowers in May-June.
Bleeding heart has pink flowers and green pea-like seeds.
Self-heal or Heal-all blue/purple flowers occur in June.
Red columbine flowers in June and attracts butterflies and hummingbirds.
Sword fern (must have a thick layer of duff)

Trees
Arbutus has messy berries for the birds. Be careful where you place these as they stain.
Garry Oak once established, provides acorns for birds and squirrels

Herbaceaus
Common camas has blue/purple lily flower in april-may.
Spring gold one of the first yellow flowers in the spring.
Seablush has clusters of brilliant pink flowers in april-may.
Nodding onion
Fool's onion
Hooker's Onion
Oregon sunshine has showy yellow flowers in early summer.
Few-flowered shooting star offers bright pink flowers in late spring.
Spreading dogbane is at its peak later in the summer.
Western Saxifrage
Western Buttercup
Roadside Rock Moss in a moss or rock garden looks great!

Trees
Red Cedar adapts to many water conditions but prefers wet
Black Cottonwood likes to keep its feet in water (and prefers more sun).

Shrubs
Red Osier dogwood provides white berries in the fall.
Sweet gale
Stink currant
Willow Salix species
Cascara provides messy berries for the birds. Be careful where you place these as birds leave droppings very frequently when eating these.
Salmonberry requires areas with at least dappled sun.
Hardhack or Spirea loves full sun.

Herbaceous
Skunk cabbage
Juncus species