Brachychiton rupestris is endemic to Queensland, Australia, but both of today’s photos are of cultivated plants in California.
This species grows as a pachycaulous tree, meaning it has an unusually thick-stemmed trunk. Young Brachychiton rupestris trees have straight trunks. As they mature, reaching the age of 5-15 years, these succulent-like trees begin to store large amounts of water between their inner bark and their trunk. The tree’s trunk swells until it becomes round like a big bottle, giving this species its common name of Queensland bottle tree. Brachychiton rupestris‘s water reserve allows it to survive extended periods of drought. It can even survive for three months after being uprooted. This plentiful source of moisture was well-used by the aboriginal people of Queensland, who would eat the secretions produced from wounds in the tree’s trunk, as well as eat most other parts of the tree.
The first photo displays the seeds and pod of Brachychiton rupestris. It forms groups of 3 to 5 boat-shaped follicles (dry fruit from one carpel that contains multiple seeds). Each follicle holds 4 to 8 (up to 12) seeds. The seeds are surrounded by a hairy coating which will irritate unprotected skin. Brachychiton rupestris seeds germinate readily and can be grown in most soil types. Botanical gardens around the world feature this awe-inspiring species, but the best place to see it is in its homeland. It is commonly planted as a street tree in Queensland. The town of Roma, Queensland, features an avenue planted with over 100 Brachychiton rupestris in honour of fallen WW1 soldiers. In the same town is the purported largest Queensland bottle tree in the world, measuring over 9 meters in circumference.
I encountered Brachychiton populneus planted along the street in San Pedro, California. I was surprised to see three trees endemic to Australia in the same neighborhood (including Callistemon (Bottlebrush tree) and Cupaniopsis anacardioides (Tuckeroo)). I guess the drought resistance is important in Southern California…
Click the link to the “largest Queensland bottle tree”. Charming slice of life of one man and some interesting pictures.
I’m thrilled to be sharing the honours with my flickr friend Mike Bush, and also thrilled to learn more about this tree. Now I’ve learned even more, as I see here and elsewhere that Brachychiton are now in the Malvaceae family. I have label photos showing it in Sterculiaceae, which is what I’d have guessed from seeing Doug’s B. populneus photo.
Thanks for all the great info on this interesting tree.
I did jump to the link for “largest Queensland bottle tree” and was delighted with the article about Roma and the fellow who is selling seedlings. And, I learned a new word: Spruik!
I also checked out Brachychiton rupestris on Google Images to see lots of pix of its pretty flowers and of other Brachychiton relatives.
Thanks so much for this great site. It’s always a treat.
😀
Jess
Very interesting indeed! The ability to hold water in its trunk for a long period of time certainly gives it an advantage in these drought stricken times. Nice photos! Congratulations, Wendy, on getting your photo published here! Hope to see you around soon!
~Trella