Fig. 24.—Red alder (Alnus oregona).
Fig. 25.—Black cottonwood (Populus trichocarpa).
Red alder (Alnus oregona) ([fig. 24]) occurs from Alaska to southern California. It is common about Mount Rainier, in river bottoms, on the banks of large streams, and in swampy places. It usually grows to a height of 30 or 40 feet. The bark varies from nearly white to light gray. It is the most abundant of all the deciduous trees in the park.
Black cottonwood (Populus trichocarpa) ([fig. 25]) is common from Alaska to southern California. It is occasionally found in the park up to 4,000 feet. It grows along streams and on sandy river bottoms often associated with the alder. The leaves are almost always in motion, very gentle winds being sufficient to make them twinkle and turn.