This beauty is the root of the Echinacea Purpurea from the family of Coneflowers.
It's quite a common plant in gardens, and it has incredible powers which are easy to extract.

In autumn you collect the roots and clean them:

Then cut them, maybe squeeze 'em a bit, put them in a glass and cover them with
70 -90% Alcohol (make sure that none of the roots are sticking out of the alcohol!):

Leave them in a spot where you have sun for half of the day. Shake daily.
After 4 weeks you pour everything through a tee- or coffee-filter and your Echinacea is ready!

Dosage:
If you feel a cold coming take 20 drops initially, then 10 drops every 3-5 hours.
If taking it for a longer period of time (e.g. for blood cleansing) you should check the correct dosage. If you take them against a cold only, for a few days, there is nothing to worry about.

If you are not a hypochonder, the roots from one plant should produce enough for a year.

Obviously the Echinacea from in front of the door is much
more efficient than the one you can buy in the pharmacy.

And here are some pictures of this beautiful plant:

Stay healthy!

^{Don't be disappointed that I'm doing a post which is not purely photography; that picture of the root makes for a great portrait!}