Identify this tree with two different types of leaves?

Question

There are 2 types of leaves sprouting from the mystery root here. You might guess that one is a sprig of tree leaves and the other leaves belong to a weed, but in fact both are growing directly from the root! In fact, the differing leaves even track back to the same stem. Can someone identify this tree, please?

Our best guesses were some type of oak tree or a jacaranda tree, but we couldn't find any similar images on the Internet. There are many trees nearby, and unfortunately, I am not in the area, so I can't photograph them all for you.

UPDATED:

Ok, here are some photos of a young tree growing in my friend's backyard that looks to be the same species. You can't see the root clearly, but the leaf pattern is the same.

Answer 1

This is some species of Acacia.

The strap-shaped leaves are actually petioles (the leaf stem) which have expanded and flattened, and do not have an actual leaf blade. This type of flattened petiole is called a phyllode.

The only acacia I've ever seen with these two different leaf forms is koa, but several (maybe most?) Australian acacias also behave this way. It's been 20+ years since I've seen a koa, but if I remember correctly, the normal-looking compound acacia leaves are actually juvenile, and as the leaf matures and the phyllode develops, the leaflets fall off, leaving just the phyllode.

Here's a picture that demonstrates the growth habit of Acacia koa: