A favorite Australian architectural tree is brachychiton rupestres otherwise known as the Queensland Bottle tree. It should not be confused with the baobab, Adansonia Gregorii, even though baobabs are also known as bottle trees. Both are a type of growth that is known as succulent or vascular vegetation. These plants have a moisture absorbing system, sort of like a tubular siphon, that stores up moisture separate from the circulating system that they use to move nutrients to their leaves and all their other parts. This allows them to take advantage of rainy seasons, storing up available moisture for the dry season.
A Literary Reference
Many of the trees of Australia are described in Flora Australiensis: A description of the Plants of the Australian Territory by George Bentham and Ferdinand Mueller published in 1863 – 1878 as a seven-volume set. As with many of these early publications, there was a good bit of political brangling surrounding the publication, and eventually Mueller came out with his own book, The systematic census of Australian Plants. The Fl. Ausral., as Bentham’s book is often abbreviated, contains descriptions of 8,125 plants. Eventually each territory in Australian published its own book, but they frequently draw on this extensive early compilation as a reference.
Brachychiton: A Very Australian Kind of Plant
There are several different kinds of brachychiton, including b. rupetris, or the Queensland Bottle Tree, which is sold by Designer Trees. B. rupetris is easy to cultivate and lends itself easily to hybridization. This, plus its unique shape and hardiness makes it an ideal architectural tree. It can even be transplanted or grown in a container; an added bit of versatility that makes it ideal for quickly putting together a landscaping scheme. As with all native plants, it is advisable to get your b. rupestris from a fully licensed nursery that is authorized to handle rare or even endangered plants. (We are fully licensed. In fact, Tony got his start by transplanting native trees that just happened to be growing in the way of construction or other sorts of development.)
When you purchase your plants from a licensed nursery, you can be assured that they are either locally grown (as are most of our trees), or they have been carefully shipped and inspected by licensed handlers. You can also be sure that they have not been illegally gathered or poached from public or private lands. This is important because such plant poaching can further damage wild flora that is already on the watch list as vulnerable or endangered. In addition, trees and other plants from licensed nurseries, such as ourselves, have been carefully inspected to be pest and disease free so that you can be sure you are not introducing a condition that might be costly or even impossible to remove from your growing spaces.
Not the Only Iconic Australian Tree
Queensland bottle trees are truly amazing, but they are certainly not the only amazing tree in Australia. Nor are we able to provide even a small representation of the broad variety of trees that are native. Perhaps one that almost any person with an interest in trees might recognize is the Eucalyptus tree. Well known for a variety of reasons, including its use in various medicines, and as a unique hardwood. But perhaps it is best known as food for koalas.
The oils in eucalyptus trees make them toxic to most animals, but koalas have a special ability to sniff out the least toxic leaves, and to quickly flush the toxins from their systems. In fact these adorable marsupials depend upon eucalyptus leaves as a main part of their diet, although they also eat material from brush box, paperbark, and bloodwood trees. As the Eucalyptus tree forests decline, so does the koala population.
Eucalyptus trees are a worry during forest fire season because the volatile oils that make them such good medicine and air fresheners are highly flammable. In California, where the blue gum (a type of eucalyptus) was imported, these trees are now a concern. This is especially true because of California’s increased rate of wildfires. Although eucalyptus make beautiful shade trees, they can be invasive in the US. More than that, it has been discovered that they can be highly toxic to some pets, especially to cats.
Perhaps the lesson here is that when trees or other plants are planted in areas where they are not native, no matter how wonderful they might be in their native habitat, they can become a nuisance when planted elsewhere.
Australia has its own problems with non-native growth. For example, olive trees are marvelous. They provide olives – with all their excellent applications as food and oil – but have adapted very well to Australia, where they can become a nuisance if allowed to grow unchecked. For these reasons (as noted elsewhere) people who grow olive trees in Australia might need to take steps to restrain unwanted growth.
It would take a book, or perhaps several books to discuss all the amazing trees that grow in Australia. But stay tuned. Next week there will be another blog, and a chance to learn more about the resilient, varied trees that grow on this amazing continent.