Chamomile is an herb used in many herbal tea mixtures designed to relax and lure the drinker to sleep. I first heard of chamomile tea when I was read Peter Rabbit by Beatrix Potter. After Peter returned from his adventures with Mr. McGregor his mother dosed him with chamomile tea and put him to bed. I tried making chamomile tea when I was a young child, but having no access to real chamomile my attempts were unsuccessful and two or three spoonsful of sugar did not help in the least.
As an adult I often noticed pineapple weed growing at the edges of my dirt driveways and got it into my head that this was chamomile. It is sometimes called wild chamomile, and pineapple weed, Matricaria discoidea, does belong to the same family as the annual German chamomile, Matricaria recutita. Pineapple weed does not have the petals that real chamomile has. As you might imagine, if you bruise the ferny low foliage you will get a pineapple scent.
I now grow Roman chamomile (Chamaemelum nobile ) in my herb garden and it is a very pretty plant. It grows only about a foot tall and has beautiful little daisy-like flowers that can be harvested and dried to make tea. It can be used as a groundcover and it seems to me I have read about chamomile lawns in English novels.
German chamomile is an annual that grows to about 2 feet, and is the variety most often grown commercially. The many uses of chamomile are listed in herbals. I have noticed that even in places where you expect clarity about the scientific names of chamomile you will find some discrepancies. It might me easier just to think about German annual, and Roman perennial chamomiles, and look for pineapple weed around your driveway or some sunny roadside.