What quality of plant is this? Ok, I have a plant that I got roughly speaking a year...

Ok, I have a plant that I got roughly speaking a year ago from a woman I used to work with. It was division a piece she accidentally broke off a larger plant and I put it in a pot with water (where it have been since) and it grew roots. I am really wanting to find out what kind of plant it is so I know the best method to plant/take care of it.

Description:
Green stem/trunk? Approx 1" diameter
Leaves are yellow-green in the middle and green on the end
The leaves grow out of the top of the trunk (start out rolled and open up)
Full plant in the department was roughly 4-6' tall & have leaves all up and down it
Leaves are approx 10-12" long and 6" wide
The trunk/stem looks similar to the top layer is constantly dying and regenerating because within is always dead matter that comes off in rows.

Ok I hold a picture but there's no place on here for me to post it. If you have any ideas or guesses please permit me know...tried to look online but it was a very daunting responsibility since I had no clue where to even commence.
Answers:    could be a dieffembachia