On the left is the fleur de lys, which is a positive symbol for French, here. (In France, it represents the monarchy, the kings and queens we've got rid of a few centuries ago and is therefore not so positive)
On the right, the Ontario flower (the trillium grandiflorum, or white trillium).
I'm sure you're better than me and can guess what the colors (white and green) represent. Now that I know the answer, I think I should have been able to find white. What's white in Ontario? Especially in northern Ontario (where you find most of the Franco-Ontarians)? Yes, snow. The colors represent the seasons. I guess there's just winter and spring since there are only two colors (and honestly, I tend to agree, since I find summer very short, and fall is like winter to me!).
And now, here is the song associated with the flag (well, at least the song Julia and Kelden learnt at school!).
Now I think I should make a family flag and have a family song!