SERIES 19 | Episode 14
The Norfolk Island pine Araucaria heterophylla is a member of the Araucariaceae family - a family of plants that goes back in the fossil record to the Triassic period, some two hundred million years ago.
The Araucariaceae includes the Araucarias. For example a tree called the Araucaria columnaris is from New Caledonia - the epicentre for the distribution of the Araucarias. Thirteen of the nineteen different species come from that part of the world.
Another wonderful tree is the Queensland kauri Agathis robusta. The Agathis are the second genus in this family. Look out for the typical flaking bark and thick leathery leaves. The third, and perhaps the most fascinating, genus is Wollemia because it was only discovered in 1994 and its single representative is the Wollemi pine Wollemi nobilis.
The Royal Botanic Gardens in Melbourne holds a great collection of these extraordinary trees both Araucarias and Agathis.
Some favourites include:
* Araucaria montana. It has the most extraordinary foliage and I'm really looking forward to watching the tree grow over the next few years.
* Of all the araucarias my favourite is the bunya bunya pine Araucaria bidwillii. It's a beautifully shaped tree and really dramatic in the landscape. It produces extraordinary cones which can easily weigh up to 10 kilograms. These are usually carried at the top of the tree and contain seeds that are delicious and rich in energy. By the time they hit the ground though, they are moving at speed, so don't picnic under an Araucaria bidwillii with cones.
If you find an Araucaria bidwillii cone, and you want to propagate it for your garden, the seeds will germinate in two weeks. Don't worry if the plant that germinates has a double stem - one will be lost as the plant matures. But growth will be quite slow after it germinates.
Not all plants in the family are easy to grow from seed and it's difficult to obtain the seed from many of them. For example an Araucaria laubenfelsii is a New Caledonian native and New Caledonia is no longer releasing seed material so nurserymen are looking at different propagation methods.
* One way is to take cuttings - although the typical habit of the branch is to grow downwards - these can be trained to a vertical habit.
* Another successful propagation method in the gardens has been to use aerial layering techniques. This method has been used to propagate an Agathis lanceolata.
* The final propagation method has been to graft species. For example an Araucaria muelleri was wedge-grafted onto the rootstock of an Araucaria cunninghamii.
Plants from the Araucariaceae family don't grow quickly. But if you have a large park or garden plant one of these trees, although you won't see the best of it yourself....you can leave it for future generations to enjoy.
Royal Botanic Gardens Victoria