Plant Collector: Castanospermum australe

A mission requiring the tall extension ladder - gathering the Castanospermum australe flowers

A mission requiring the tall extension ladder - gathering the Castanospermum australe flowers

It was just a little difficult to photograph the orange pea flowers on the castanopsermum, owing to the fact that they are at least 10 metres up the tree and beyond the limit of my camera’s zoom. Getting this photograph entailed Mark on the end of the extension ladder cutting a branch to bring down to ground level. The tree itself is probably getting closer to 20 metres now, though it has taken several decades to get there. I was slightly alarmed to see that it has the potential to reach 40 metres high in its natural habitat of east coast Australia, particularly Queensland, but I doubt that it will reach that in our cooler climate, or indeed in my lifetime.

The common names for this plant are Black Bean Tree (on account of its large black seeds held, as legumes are, in a pod) and Moreton Bay Chestnut. Indeed castanea means chestnut in Latin and that is where it gets its name from. It has always been much on my conscience that many years ago when we sold a few of these (and painfully slow they were, to get grown to saleable size), in my ignorance I assumed that the common name of Moreton Bay Chestnut meant the seeds were edible. They can be eaten – if you are Aboriginal and understand the painstaking process of rendering toxic seeds edible (a bit like karaka berries in this country). Lacking that knowledge, poisoning is more likely. As the tree takes some time to flower, I am hoping that my incorrect plant labels will long since have faded into oblivion so nobody tries eating the seeds.

The tree is evergreen and has handsome, pale green, large pinnate leaves – pinnate meaning divided like a feather. Should it outgrow its space here, apparently the timber is attractively grained like walnut.