Most conifers are evergreen (do not lose their leaves in winter), are pollinated by wind, have cones and do not have flowers. The main distinguishing characteristic of a conifer is that the seeds are not enclosed in a fruit they are said to be naked (see diagram ). Conifers share this characteristic with other gymnosperms like Ginkgo trees and cycads.
The leaves of conifers are usually narrow, often resembling needles, or are reduced to small scales along the branchlets such as found in the Cupressaceae family. These needle-like leaves are tolerant of cold and help the tree reduce water loss.
A few species have the more familiar broader leaves, such as the Kauri pines (Agathis species). The pines and cedars (Family Pinaceae) have long narrow needles clustered in short shoots, while the Celery-topped Pine (Family Podocarpaceae) has flattened branchlets called phylloclades which resemble leaves.
Although the majority of conifers are evergreen and renew their leaves year round, some species, such as Bald Cypress and Dawn Redwood (Family Taxodiaceae), are deciduous.
Sometimes the juvenile leaves of conifers are very different from the adult leaves. This is well illustrated by the rare conifer, Wollemi Pine, (Wollemia nobilis) which has stiff dull yellowish green adult leaves arranged in four rows on the upper surfaces of the branches. The juvenile leaves are soft, dark green on top and waxy white underneath, and are arranged in two rows on the branches.
The main groups (genera) that are native to Australia are :
¥ cypress pines (Callitris species)
¥ plum pines (Podocarpus species)
¥ kauri pines (Agathis species)
¥ Tasmanian cedars (Athrotaxis species)
¥ Celery-topped Pine (Phyllocladus species)
¥ Huon Pine (Lagarostrobos franklinii)
¥ Bunya and Hoop Pines (Araucaria species).
The common plantation pine trees (eg. Pinus radiata) are not native to Australia but in some places have become naturalised (can exist on their own in the wild). Many of our native conifer species are not found anywhere else in the world, that is, they are endemic to Australia.
Many of the Australian conifers are limited in distribution, and are
much less abundant than they were before European settlement due to logging
and their vulnerability to fire. This has lead to some species, such as
the Huon Pine (Lagarostrobos franklinii), being completely protected