Tall Ambrosia

Debility with a bitter, weak digestion following a low intermittent fever, where a plain bitter tonic is wanted rather than a stimulating one

A fresh insect sting or minor wound where a bruised-leaf poultice is at hand and a quick astringent, hemostatic dressing is wanted

Overview. Ambrosia trifida is a tall, coarse annual of the Asteraceae family, native to much of North America and now widespread as a weed of disturbed ground, riverbanks, and cultivated fields. The Eclectic physicians of the nineteenth century used the fresh leaves and flowering tops of this and the related smaller ragweed, Ambrosia artemisiifolia, as a plain bitter tonic and mild antiperiodic, and applied the bruised herb topically to stings, bites, and small wounds. It is far better known today as one of the principal sources of allergenic pollen behind late-summer hay fever than as a medicinal plant, and its use in practice is now uncommon.

Clinical Notes. Where this plant appears in the older American literature, it is almost always alongside its smaller relative Ambrosia artemisiifolia, and the two were used somewhat interchangeably as a simple bitter tonic for weak appetite and sluggish digestion, particularly in convalescence after a low fever.