Araucaria heterophylla

Cook Pine & Norfolk Island pines.

Araucaria columnaris, the Cook Pine and Araucaria heterophylla, the Norfolk Island Pine.
These two are closely related and very similar in appearance resulting in many being mis-named.
They are rarely seen in Australia and then mainly in public places and they are not named.
Specimens of Araucarias in botanic gardens are not always named.

Various people use different (often not very scientific) criteria to distinguishing the two species.

Descriptions of a particular species can be very different e.g. one says a pollen cone is 5 cm long and
    another says it is 10 cm; one says a juvenile leaf is 7 mm and another says 13 mm.

Reading descriptions of the two trees can make it sound easy to tell the difference e.g. Cook are narrow and
    columnar in shape while Norfolk are triangular.
However there are variations in morphology depending on factors such as where they are growing.

According to Flora of Australia Vol 48 both have mature leaves that are flattened (no keel) and under 1 cm long.
    Norfolk Island adult leaves are 5 to 10 mm long; Cook are under 4 mm.
   The terminal branchlets in Norfolk pines are erect; in Cook they are drooping.

I have only seen 2 named Araucarias and both were Hoop pines.

J.F.