I have an Australian bottle tree that's about 12 feet tall, but it must have suffered some sort of trauma earlier in its life because the bottom half is misshapen and the top half seems to have sprouted from the damaged trunk. If The top half (about 1 inch diameter) can be layered, it would make a fine tree in time.
Virtually, any tree can be a good candidate for layering. It is always best to make sure that there are replacement branches in case the project fails, but as long as you know the proper technique then you can air-layer almost any tree. This article will help: https://www.gardeningknowhow.com/garden-how-to/propagation/layering/air-layering-plants.htm
Some leaves have 3 pieces others only 1
Eventually, all of them will have a collection of, both, simple and divided leaves! This is natural, and is not a reason for concern.
This article will help you with its care:
https://www.gardeningknowhow.com/ornamental/trees/bottle-trees/growing-kurrajong-bottle-tree.htm
I have 2 small Australian bottle trees, Brachychiton rupestris, in pots and are ailing. I am attaching photos. Do you know what is happening to the leaves? Is this how they begin to lose leaves? I live in southern New Mexico, zone 8. The potted plants are on the patio in the summer with partial direct sun and temps in high 90s. In the winter I bring them inside.
Usually, brown leaf tips indicate improper watering. However, I also see mottled leaves, a sign of spider mites. Check for those and make sure you aren't over or underwatering.
https://www.gardeningknowhow.com/plant-problems/pests/insects/spider-mite-treatment.htm
https://www.gardeningknowhow.com/ornamental/trees/bottle-trees/growing-kurrajong-bottle-tree.htm
Noticed it after heavy rain.
This can definitely happen after heavy rainfall. It isn't usually a big concern. I don't really see any signs of infection. I do see lichens, but those are typically harmless. If you notice a strange smell, then you may want to treat with fungicides. Otherwise, keep caring for the tree as usual.
https://www.gardeningknowhow.com/ornamental/trees/bottle-trees/growing-kurrajong-bottle-tree.htm