A large tree up to 130 feet tall, with a swollen base. Pyramidal growth habit, or else with an open, flat-topped crown. Often has cone-shaped “knees” emerging from roots of the tree if growing in water. Loses its leaves in the fall.
Leaves needlelike, opposite, in 2 rows along small twigs. Each leaf is ¼-¾ inch long, flat, linear, green, turning reddish-brown in autumn. Leaves are shed in autumn still attached to the small twigs.
Bark cinnamon-brown to gray, thick, with long, narrow grooves and flat, long ridges that peel off in fibrous, narrow strips.
Twigs light green on new growth, turning reddish brown with age, smooth, flexible. Side twigs green, falling with leaves still attached.
Flowers March–April. Male and female cones are found on the same tree.
Fruit, October–November, is a round cone 1 inch in diameter, green changing to purple, with tightly closed, shield-shaped scales that turn woody and brown and open at maturity to release seeds.