Epimedium flavum (barrenwort)
Epimedium flavum is a herbaceous perennial with upright stems and bright yellow flowers, produced mainly in spring.
Yellow flowers of Epimedium flavum
Epimedium flavum Stearn
barrenwort, tian quan yin yang huo (China)
Vulnerable (VU) according to IUCN Red List criteria.
About this species
More species of Epimedium grow in China at elevations between 500 m and 3,700 m in the woodlands of Sichuan Province in than in any other region. One of these, Epimedium flavum was first collected there in 1992 and named in 1995 by the British botanist William Stearn. Two other yellow-flowered species from the same area are similar: E. davidii (with smaller, red inner sepals, usually larger leaves and compact rhizome) and E. fangii (pale reddish inner sepals and creeping rhizomes).
William Stearn named Epimedium flavum and many other species of Epimedium and wrote the monograph, The Genus Epimedium and other Herbaceous Berberidaceae, published by the Royal Botanic Gardens, Kew in 2002.
Geography and distribution
Epimedium flavum is found in Sichuan Province (Tianquan Xian, on the eastern side of Erlang Shan), central China, at elevations of 1,800–2,000 m.
Overview: Epimedium flavum has a compact rhizome and forms dense clumps, reaching up to 30 cm tall.
Leaves: The leaves have five (sometimes three) leaflets. The leaflets are heart-shaped, rounded and have sharp teeth around the margin.
Flowers: It has 3–10 sulphur-yellow, long-spurred flowers on upright stems. The flowers are around 3 cm across and have four inner sepals 11 mm long with rounded petals and slightly curved, spreading spurs.
Threats and conservation
Epimedium flavum is included on the IUCN Red List of Threatened Species as Vulnerable (VU D2). Species listed as VU D2 face a high risk of extinction because of their limited distribution (ie restricted area of occurrence or small number of locations) and are vulnerable to the effects of human activities or random disasters. They may therefore become Critically Endangered or even Extinct in the short term.
Epimedium flavum is grown as an ornamental.
This species at Kew
Epimedium flavum is growing in the Woodland Garden.
Pressed and dried, and alcohol-preserved specimens of Epimedium flavum are held in Kew’s Herbarium, where they are available to researchers from around the world by appointment. The details of some of these specimens can be seen online in the Herbarium Catalogue.
Illustration from Curtis's Botanical Magazine
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Published for the Royal Botanic Gardens, Kew by Wiley-Blackwell Publishing.
China Plant Specialist Group (2004). Epimedium flavum. In: IUCN Red List of Threatened Species. Version 2011.1, IUCN 2011. Available online (accessed 13 September 2011).
Stearn, W. T. (1995). New Chinese taxa of Epimedium (Berberidaceae) from Sichuan. Curtis’s Botanical Magazine 12: 15-25.
Stearn, W. T. (2002). The Genus Epimedium: and other Herbaceous Berberidaceae. Royal Botanic Gardens, Kew.
The Plant List (2010). Epimedium flavum. Available online (accessed 13 September 2011).
Ying Junsheng, Boufford, D. E. & Brach, A. R. (2011). Epimedium. In: Flora of China. Vol. 19, eds Wu Zhengyi, Raven, P. H. & Hong Deyuan. Science Press, Beijing & Missouri Botanical Garden Press, St Louis. Available online (accessed 13 September 2011).
Kew Science Editor: Martyn Rix
Copyediting: Malin Rivers
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