Plant used in herbal medicine (6)
(Other definitions for hyssop that I've seen before include "little blue flowers" , "Aromatic herb" , "Small bushy plant with bitter minty leaves" , "Plant with minty leaves used in cooking or as medicine" , "Aromatic plant" .)
(Other definitions for yarrow that I've seen before include "Aromatic wild flower" , "Strong-scented creeping plant, once used in herbal medicine" , "Perennial herb, milfoil" , "Creeping plant, also called milfoil" , "Herb; a worry (anag.)" .)