Epimedium grandiflorum, the large flowered barrenwort, or bishop's hat, is a species of flowering plant in the family Berberidaceae, native to China, Japan and Korea. It is known as dâm dương hoắc in Vietnamese.
It is a deciduous perennial growing to 30 cm (12 in), with bright red stems with green heart-shaped leaves (copper-tinged when young) which are slightly hairy on the bottom. In spring it produces pink, white, yellow or purple long-spurred flowers.
- E. grandiflorum
- E. grandiflorum 'Nanum'
- E. grandiflorum 'Rose Queen'
- E. grandiflorum 'White Queen'
Traditional Chinese medicine
E. grandiflorum may have anti-impotence properties due to the presence of icariin, a relatively weak inhibitor of PDE5 in comparison to substances like sildenafil (viagra). Western peer-reviewed research into the efficacy of E. grandiflorum as an aphrodisiac is lacking; however, the herb has been used for this purpose in traditional Chinese medicine and is a common ingredient of herbal remedies for impotence. It is commonly packed in a capsule with other ingredients or sold as herbal flakes or powder with the name "horny goat weed".
- "Epimedium grandiflorum". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved 2010-05-25.
- RHS A-Z encyclopedia of garden plants. United Kingdom: Dorling Kindersley. 2008. p. 1136. ISBN 1405332964.
- "AGM Plants - Ornamental" (PDF). Royal Horticultural Society. July 2017. p. 35. Retrieved 6 February 2018.
- "RHS Plant Selector - Epimedium grandiflorum". Retrieved 18 June 2013.
- "RHS Plant Selector - Epimedium grandiflorum 'Nanum'". Retrieved 18 June 2013.
- "RHS Plant Selector - Epimedium grandiflorum 'Rose Queen'". Retrieved 18 June 2013.
- "RHS Plant Selector - Epimedium grandiflorum 'White Queen'". Retrieved 18 June 2013.
- "HORNY GOAT WEED: Uses, Side Effects, Interactions and Warnings - WebMD". www.webmd.com. Retrieved 2017-10-20.