Turnera diffusa – Damiana (plant)
Turnera diffusa is an aromatic shrub from 1 – 2 metres tall, with erect stems bearing small, simple toothed leaves and yellow solitary flowers borne throughout the year. Native to tropical America (Mexico, Caribbean Islands and southern California) where it is cultivated to a limited extent, most of the dried herb material is obtained through wild harvesting. It is found in dry, sandy or rocky places. In the Turneraceae family, the Turnera genus contains approximately 60 species.
The dried leaves are used as a general tonic and a traditional aphrodisiac. No clinical evidence has supported its use as an aphrodisiac although anti-depressant properties have been noted. It has a long history of use in traditional medicine throughout the world and has been reported as an astringent, diuretic, expectorant, laxative, nervine, purgative, stimulant, tonic and used for venereal diseases (Melendez et. al. 2004).
Dried leaves are used in teas, smoking mixtures and an extract is used to make the liqueur Damiana which is popular in Mexico as an alternative to Cointreau. The herb contains an essential oil, the main constituents being caryophyllene oxide, caryophyllene, cadinene, elemene and 1,8-cineole (Melendez et. al. 2004). Cadinene is reported as being a testosterone inducer and 1,8-cineole as a testosterone hydroxylase inducer (Melendez et. al. 2004).
Care and Cultivation of Turnera diffusa
Turnera diffusa likes a full sun position in dry to semi-moist soil. Sandy well drained soil. Should be kept less moist in winter to discourage fungal diseases. High humidity combined with low temperatures often result in fungi attack and dieback. Fertilise moderately during the growing season. Cut back in spring and summer to encourage new growth. Likes a lot of root space but can be kept trimmed in the same pot for a number of seasons. Extremely drought tolerant.