In the lush understory of the temperate rainforest communities, the prickly stalks of devil's club (Oplopanax horridus) poke their large leaves into lit openings and spindly vine maples (Acer circinnatum) arch among the trunks of the huge conifers. The understory feels ancient because the simple rosettes of sword ferns (Polystichum munitum) are clumped around the bases of the trees and mixed in the understory are deer ferns (Blechnum spicant). Other more delicate ferns, such as the maidenhair spleenwort (Asplenium trichomanes) and the northern maidenhair fern (Adiantum pedatum) can be found tucked around rocks and on slopes. As in the coastal forests, some of the most common flowering plants are May-lily (Maianthemum dilatatum), Oregon wood-sorrel (Oxalis oregana), and Siberian miner's-lettuce (Claytonia sibirica). Dense patches of Oregon wood-sorrel sometimes cover the ground or even the surface of a fallen tree that has begun to decay. Along the creeks in spring you can find the bright yellow hoods of skunk cabbage (Lysichiton americanus) that hold inside a thick stalk of simple white flowers; but as the bright yellow hood withers in the late spring, the plants begin to form a rosette of large, succulent leaves.

Devil's club	Vine maple	Sword fern
Deer fern
May-lily	Wood-sorrel	Siberian miner's-lettuce
Skunk cabbage