As another blood thinner patient, I learned some interesting info from one the visitors to my hosp. while i was it (from pulmonary embolism..
blood clot in the lung) that one form of the drug Coumadin is called Warfarin, and that stands for Wisconsin Alumni Research Foundation, the group that discovered the blood thinning properties from coumarin, improperly cured clover hay...www.warf.org/

info :

Coumarin is found in several plants, including tonka beans, lavender, licorice, strawberries, apricots, cherries, cinnamon, & sweet clover.
Properties
Coumarin has blood-thinning, anti-fungicidal and anti-tumor activities. .... Coumarin increases the blood flow in the veins and decreases capillary permeability. ...
Facts about Coumarin
Coumarin seems to work as a pesticide in the plants that produce it. Coumarin is responsible for the sweet smell of new mown hay.

(the good news is that it might also have anti-fungal and anti-tumor
properties, the bad news is that is used for rat poison)