I'm sure I'm spelling it wrong, but it looks like a shiffirella - spelled phonetically, of course. ;0)

Your right corar, for easy spelling I call it an umbrella tree!

Yeah, schefflera actinophylla, most likely. It will become a huge tree and is considered an invasive, although not a particularly evil one:

Here is a link that might be useful: schefflera actinophylla at UF

Where the heck did it come from? I don't have any on my property or even see them growing anywhere.

Thanks,
Jane

Birds and other critters spread the seeds.

Yes, that's how invasive plants escape gardens and invade the wild areas.

My advice is to get rid of it. Save your Christmas cactus.

I hate schefflera. It IS invasive here. The birds (or critters) planted one in the middle of my huge bird of paradise. It was well established before we noticed it. We had to dig up the bird and dig out the stump and roots. We used a come-along and truck to pull it out. On the up side, we gave away 8 birds to several people and all are doing well, including the mother plant.

Our landscaping was well established when we bought the house. I had a big bush-style shefflera at the side of our house - too close to the foundation and under a window. I decided it had to go. It was then that I realized that shefflera drop air roots and establish new trunks with its own root system. It was a jungle. To make matters worse, the horrendous root system was near and around my water pipes!

I spent a couple of weeks chopping off stems, pulling up roots and finally getting to the main plant - which had huge roots going under the foundation. This is the stump of the main plant. It is 3 feet tall. The roots ran all the way to the left edge of the picture.