Common Plantain is indeed a very common weed just about everywhere. I've seen it all my life and never even knew what it was until recently, when I started reading about herbal medicine.
According to this page, Plantain has been used medicinally since ancient times. It was listed as one of the nine sacred herbs in Anglo-Saxon medicine because of its healing properties, and both Chaucer and Shakespeare make mention of its healing abilities in their writings.
The property of plantain which most interests me is its supposed ability to take the itch and pain out of insect bites. Every book or webpage I read mentions this about the plant, so I thought it was time to try it out for myself.
Even our tiny backyard yielded a good sized handful of plantain leaves when I went looking. I washed off the leaves, then let them dry in the hot sun until they were wilted (I figured it would be a bad thing to have too much moisture in a salve). I chopped the leaves fine, then I "cooked" them very gently in a half cup of coconut oil, being careful not to let it boil. Basically, I just kept the oil good and warm. (A double boiler would be good for this but I didn't bother to get mine out from the back of the cupboard.)
I have to say, while the chopped leaves were warming they actually smelled very appetizing!
After several hours, the oil turned a nice green colour. I filtered out the plantain, added 1/2 an ounce of grated beeswax, and returned it to the heat just to melt the beeswax. I poured the salve into small tins (which I bought from here) and let it harden.
Kira and I both tried the salve (which smells exactly like spinach) on mildly itchy mosquito bites last night, and found it took the itch completely away. So, so far so good. When I make a general healing salve later in the year, I will definitely be adding plantain for its anti-itch properties.
Everyone reading this probably has plantain in their own backyard. If you have some beeswax and coconut or olive oil handy, I recommend giving this a try.