This section is from the book "A Practitioner's Handbook Of Materia Medica And Therapeutics", by Thos. S. Blair. Also available from Amazon: A Practitioner's handbook of Materia Medica and Therapeutics.
Damiana, Turnera aphrodisiaca, is a native of Mexico and employed there in exactly the same manner as we use tea here, and is regarded as a pleasant, gentle stimulant without after-effects, and is not generally regarded in the light of a drug. There is no scientific evidence in favor of the claim that it possesses marked aphrodisiac properties. See the Pharmaceutical Review, Vol. 22, p. 126, for an exhaustive study of the plant.