This section is from the book "Botanic Drugs Their Materia Medica, Pharmacology and Therapeutics", by Thomas S. Blair. Also available from Amazon: Botanic Drugs, Their Materia Medica, Pharmacology and Therapeutics.
Orris, Iris Florentina, I. Germanica, I. pallida. Very generally official, but not in the U. S. P. A gastric stimulant used in breath perfumes and dentifrices. It has an action similar to euonymus, but is little used now as an internal remedy, being apt to create gastric disturbance. Dose, 10 to 30 grains.
Blue Flag, Iris versicolor. Not official now, but is listed in the National Formulary. This is the species common in the U. S. Like the Iridaceae generally, it is possessed of acrid properties. The best preparation is a saturated tincture made from the fresh root. The fluid preparations disintegrate in time.
In full doses iris is an active emeto-cathartic quite violent in action. In smaller doses it acts much like podophyllum. It is an admirable remedy in sick headache and as a mild cholagogue.
Like many of the acrid drugs with eliminative properties, iris is an alterative if continued in small doses for a long period; it stimulates the glandular system, and has an influence in reducing soft glandular enlargements with no specific pathology. As vegetable "alteratives" go, it is a good one.
The fl. is used in doses of 1/4 to 5 minims.