Agrimony Herb

Agrimony is usually common enough to harvest freely in the wild, as long as you take only a small portion from any given area.

Tie in small bundles and hang in a dark, dry place for a few days to a week depending on temperature. Or place small amounts in large paper bags.

Dry herbs in well ventilated areas away from smoke, pets, and rodents. Harvest Agrimony seeds in late summer or early fall, and plant right away or store in freezer.

History and Folklore
Witches used it in spells to dispel negative energies, and to ward off hexes.  Agrimony was said to cause a deep sleep. When placed beneath a mans head this sleep would last until it was removed. This passage is from an old English medical manuscript:

If it be leyd under mann's heed,
He shal sleepyn as he were deed;
He shal never drede ne wakyn
Till fro under his heed it be takyn.'

Author Jessica Houdret says The Anglo Saxons included Agrimony in charms and dubious preparations of blood and pounded frogs.