Mullien Verbascum Thapsus

Considered a weed. Grows along rail-road tracks, roads, paths, in rocky soil.
The seeds are mildly narcotic, but also toxic, so it's best to avoid using them for medicine.
The leaves are furry and soft, with yellow flowers.
Teas made of the leaves are used for various ailments. Such as coughs(unproductive or productive), bronchitis, sore throat and hemmeroids.
Oils from the plant are used for things such as ecszema, hemmoroids, earaches, frost-bite, and colics(use topically aka on the skin not inside the body). It is an emollient.
Sailors used to smoke this plant when they ran out of tobacco on long voyages. It by no means is a replacement for tobacco and many find it very harsh as it burns hot. Though it is a good filler for a medicinal herbal blend. Just make sure to cure it as you would any other herb used to be smoked.
I find the leaves are best when the plant is young, and very fuzzy. The fuzzier the better.
If your going to harvest from these plants, it is your duty to find a full grown one after it has already flowered and shake it's flower pod and spread the seeds, so it comes back for years to come.
In Mysticism it is considered to give off good energy to ward away evil spirits.
(for more info)
Verbascum thapsus - Wikipedia, the free encyclopedia
edit - Thanks for the pictures of the yarrow. Driving to school today I spotted a bunch of it on the side of the road and had a name to put with a pretty face.