Yarrow, noted for its long straight stalks gives a numerical answer and was preferred in the Zhou Dynasty c. 300 BC. The yarrow used in divination was the Siberian variety, achillea sibirica or achillea mongolica.
The flowers are white turning pinkish, giving off a yellow dye when boiled. Its many medicinal properties which were respected by ancient peoples.
Dense clusters of white flowers top aromatic, fern-like foliage. Mature plants are drought-and-heat-tolerant. Use the easy to grow plants in borders, wildflower gardens, and meadows. Divide clumps every 2-3 years. To dry flowers, harvest blossoms at their peak and hang upside down in a cool, dry place. - Found on the back of a seed packet.
"Because these wise men knew equally well the laws of the universe and what was needful to man, they invented the use of yarrow stalks-'those divine things."
The Great Treatise
"The nature of the yarrow is round and spiritual."
The Ta Chuan / The Great Treatise