It's grown quite tall around 40cm, in the pot where I plant a pomegranate tree (still a small tree). Thinking to uproot it if it's a weed tree. 
gardengus said:sycamore tree
Silversurfer said:
Hold on...
Acer pseudoplatanus,...common name Sycamore has leaves opposite each other on a branch.
1.This plant has alternate leaves so cannot be Sycamore!
2. It has tiny jagged leaves at the base of the leaf, like a ruff ...called stipules. Sycamore do not have these.
I should know better , It can cause confusion 
sooby said:
American sycamore, Platanus occidentalis, does have stipules and alternate leaves, but the leaves look somewhat different from the ID plant:
http://www.namethatplant.net/p...
