I just have some discovery. I can use microscope to help identify
the grass/weed. Identify might be a strong word, but it can definitely
separate some hard to distinguish grass using very small piece of grass
blade. For me, the young broom grass and TTTF are very hard to
separate. They both have harsh blades and rough edge.

Here is a Poa A edge


Young TTTF:


Young broom grass:


If you look closely, the shape of the serration is quite different.
The TTTF has more smooth hump in the back, it is very unique in all the
grass I have saw. The broom grass doesn't.

There are more feature we can use under microscope. Now I can separate
TTTF with broom grass with a high confidence level, using the microscope.

The best part is, it only needs 2mm grass blade. I can put a few of them
on the slide together, just move the slide to compare them. Feels like CSI,
for the grass!