Sitka alder (Alnus sinuata) belongs to the family Betulaceae (the Birch family). It is a small deciduous tree that is native to western North America, from Alaska to California east to Idaho and Montana. This small grows in moist woods, stream banks and moist montane slopes, and it can reach 6-12 m in height. The barks are gray to grayish green with warty lenticles. The leaves are alternate, ovate to oval, with sharply and doubly serrate margins. The male catkins are long, slender, and pendent. The female catkins are small and hang in long clusters from long stalks. It is in flower from April to June, and the seeds ripen from July to August. The fruits are small semi-woody cone 1.5-2.5 cm long, and persist through the winter.