Is this a Herb

I found this plant in my garden. Is this a herb or a weed? It is about 30" tall and have no scent.

 

I'd suspect a species of Anthemis, though they are usually aromatic.

 

Most probably Tripleurospermum inodorum (scentless mayweed / false mayweed / false chamomile). It is a noxious weed, introduced in North America. T. perforatum is a synonym. Earlier, the species also has been treated under the genera Anthemis and Matricaria.

Of course, it is a herb and a weed (and a plant) at the same time!

Cheers,
Harri Harmaja
http://www.fmnh.helsinki.fi/users/harmaja/about_myself.htm