Araucaria columnaris is an evergreen tree that reaches up to 50 m of height with numerous horizontal lateral branches, producing the effect of a very dense and characteristic column.
The trunk has dark, rough and scaly brown bark that is peels off in thin horizontal strips. The leaves juvenile plants are narrowly triangular, to 12 mm long, and needle-like. Adult leaves are widely ovate, about 6 mm long, rigid, usually broadly scale-like, spirally arranged or nearly 2-ranked, usually closely overlapping, flattened, persistent for many years. The male cones hang at the tips of the lower branches and are cylindrical and 6-8 cm long. The female cones are erect, green, globose-ellipsoid and produced in the upper branches. These may be up to 12 cm of diameter, with sharp tips at the ends of the scales. When mature the cones shatter to release the reddish brown scales about 4-5 cm in length, which bear the seeds.
Araucaria columnaris is often confused with Araucaria heterophylla, but that species has leaves that are more than twice as long.
(Preda, Milea. 1989. Dendrofloricol Dictionary.)