I'm not familiar with that plant, but it seems it could be spelled two different ways. These first pics are with your spelling and the second is the other spelling.
Omolanthus populifolius
http://images.google.com/images?hl=e...-8&sa=N&tab=wi
Omalanthus populifolius
http://images.google.com/images?hl=e...-8&sa=N&tab=wi
What do you think?
Newt
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.