Prevalence: Abundant Elevation: Low to mid-elevation rivers and streams and moist slopes throughout the park Flowers: Reddish hanging spikes called catkins that appear before the leaves; male catkins 2-5 in (5-12 cm) and female catkins 0.7 in (2 cm) long Seeds: Brown cones with winged nutlets that stay on the tree during the winter
Red alders are named for their reddish appearance in the spring when they are covered in catkins before the leaves appear. Leaves are alternate, oval, single-toothed, and with in-rolled edges. 5-6 in (5-15 cm) long, the leaves are also dark green and smooth on top, hairy and reddish underneath. Bark is grey and can be patchy with lichen. Red alder, in partnership with bacteria in their roots, can remove nitrogen and "fix" it (store it) in their roots, allowing alders to colonize rocky ground along rivers and other disturbed land unsuitable for most plants. They are fast growing and can be up to 80 ft (25 m) tall.
Maple - Family Aceraceae
Bigleaf Maple Acer macrophyllum
Prevalence: Scattered Elevation: Low elevation river and stream areas, primarily on the southwest side of the park Flowers: Greenish-yellow, on short stalks hanging in a cylindrical cluster Seeds: Paired, winged seeds in a "V" shape, 1-2.5 in (3-6 cm) long
Bigleaf maple is a large tree that can be up to 100 ft (30 m) tall. Leaves are divided into 3-5 deep lobes and can be 12 in (30 cm) across! The leaves are dark green, paler underneath, and turn bright yellow in fall. Bigleaf maple trunks often support thick layers of moss and other plants, more than any other tree in the park. If not covered in moss, the bark is green and smooth in younger trees, becoming grey-brown and spotted with lichens in mature trees.
Vine Maple Acer circinatum
Prevalence: Abundant Elevation: Low to high elevation forests throughout the park Flowers: White clusters with red sepals Seeds: Red, winged pairs that spread wide to form a flat line, 0.7-1.5 in (2-4 cm) long
Vine maples are often shrub-like, but can be 16-30 ft (5-10m) tall with multiple trunks. Often an understory tree, their trunks can spread out horizontally to reach sun gaps, giving them a "vine"-like appearance. They are also common in open slopes along river drainages. Leaves have 7-9 toothed lobes and are bright green in summer, but turn a brilliant orange-red in fall. Bark is pale green in young branches, turning brown with age.
Willow - Family Salicaceae
Black Cottonwood Populus balsamifera
Prevalence: Abundant Elevation: Low to mid-elevation river and stream areas throughout the park Flowers: Catkins, with male and female on separate plants: male catkins 1.3-2.3 in (3.5-6 cm) and each flower with 30-60 stamens; female catkin 2-4 in (5-10 cm) and each flower has 3 stigmas Seeds: Round and enveloped in white, cottony hairs
Black cottonwoods have straight trunks and can be up to 160 ft (50 m) tall. Leaves are alternate, heart-shaped to oval with a sharply-pointed tip, and a fine-toothed edge. Leaves turn yellow in fall. Buds are sticky with resin that has a sweet, balsamic fragrance. Bark is dark grey and deeply furrowed in older trees.