Herb
A battlefield plant with lace for flowers, and the stalks of the oldest divination still in use.
These are associations the community holds, not settled fact — the more a reading is shared, the bolder it sits.
Yarrow's Latin name points at Achilles, who is said to have carried it to staunch his soldiers' wounds; English kept the same idea in names like soldier's woundwort, nosebleed and staunchweed. It grows in ordinary grass everywhere, feathery-leaved and flat-topped, and is easy to walk past for years without seeing.
Two quite separate practices attach to it. The first is wound-herb and protection: bundles at the door, yarrow at a wedding, yarrow against ill-wishing. The second is divination — the dried stalks are the traditional instrument of the I Ching, cast in a slow counted procedure that predates the coin method by a long way, and in English folk practice a yarrow leaf up the nose was used to settle whether a lover was true, which is a less dignified use of the same idea.
Modern practice tends to reach for it in courage and boundary work. Its reputation as a wound herb is genuinely old, which is not the same as saying it works; anything more than a passing scratch belongs to a doctor.
Readings practitioners have offered, ordered by how many recognise them. Take what serves, leave the rest.
Carried forward
Chinese divinatory practice, Zhou dynasty onward
The stalks are the classical instrument for consulting the Book of Changes, sorted and counted in a procedure that takes far longer than throwing coins. The slowness is generally understood to be the point rather than an inconvenience.
Carried forward
Nicholas Culpeper, The Complete Herbal (1653)
Culpeper places yarrow under the influence of Venus, and passes on the common seventeenth-century claim about the ointment healing wounds — while noting, in his sideways fashion, that other people say it does the opposite. He does not resolve the disagreement.
Credit what you carry. Much of this comes from living traditions, and some of it from traditions that are closed — held by particular peoples and not offered for general use. Where you know whose practice a reading came from, name them; where you don't, say that too.