I will have to find the sites because I didn't save them. My guinea pigs and rats do eat lemon grass, and it is edible, but most people don't eat it because it is woody. Ziva didn't actually eat it though, she just shredded it up. She also likes the seed heads of fox tail grass, and she shreds the blades of the grass too. I use to give this to my parakeets years ago. I let the grass grow for my guinea pigs too. Pigweed is another common 'weed' that my guinea pigs love, and I know the seeds are edible. Broad leaf plantain seeds are also edible. I don't use any chemicals at all on the yard so I don't have to worry about that. Also, any time I try a new food for any of my animals I only give them a tiny amount, after making sure it is safe for them of course.
Oh, when you buy lemon grass in the store they only sell the base of the plant, which is fairly woody. I grow it in my garden, it is about 4-5 feet tall right now, and is a grass. I will try to get a photo to show you what it looks like.