What am I? Tropical house plant, "umbrella tree"

Hi all! I'm trying to find out what in the world this plant is called. We always called it either umbrella tree or umbrella plant (Don't remember for sure which)  while I was growing up.  
Mom always kept one or several, and it seems like they reproduced quite a bit and she was always giving them away. (Even with all the changes there over the years, there still a good one in the dining room. It just wouldn't be the same without one!)
A little bit of web searching in Wikipedia hasn't turned me up anything under either of those names, so I thought I'd turn to the helpful folks here!

maybe  a dieffenbachia?  some images here most look bushier but some seem to be tall like yours and have similar leaves.

The name popped into my head when I saw your picture, not sure why as I don't have one

Judith Browning wrote:maybe  a dieffenbachia?  some images here most look bushier but some seem to be tall like yours and have similar leaves.

The name popped into my head when I saw your picture, not sure why as I don't have one

Thanks a lot Judith !  I think you're probably exactly right. Some of those pictures look just like it. Even the warnings I found about it being poisoned this ring a bell. (Which of course prompted my brother to eat a small bit of leaf one time…)