|Jeffersonia diphylla from Britton & Brown 1913|
Barton 1793 not Brickell 1800 (syn of Gelsemium in Loganiaceae)
Jeffersonia which is also known as twinleaf or rheumatism root, is a small genus of herbaceous perennial plants in the family Berberidaceae. They are uncommon spring wildflowers and grow in limestone soils of rich deciduous forests. Jeffersonia was named for United States President Thomas Jefferson by his contemporary Benjamin Smith Barton. This genus was formerly grouped in genus Podophyllum. Twinleaf is protected by state laws as a threatened or endangered plant in Georgia, Iowa, New York, and New Jersey.
The leaves and flowers of this plant are smooth and emerge directly from the rhizome at base of the plant. Jeffersonia has showy white flowers with eight petals; the flower resembles bloodroot. The short-lived flower appears in April or May, before the forest canopy appears (see spring emphemeral). The fruit is a green pear-shaped capsule with a hinged top. The characteristic leaves are large and nearly divided in half, giving rise to its common name, twinleaf. Plants in this genus rarely grow taller than 12 inches (30 cm). As with many other deciduous forest plants, the seeds are dispersed by ants, a process known as myrmecochory.
- accepted species
- Jeffersonia diphylla (L.) Pers. – Eastern North America especially Great Lakes region, Ohio Valley, and Appalachians
- unresolved names
- Jeffersonia dubia (Maxim.) Benth. & Hook. f. ex Baker & Moore – China, Korea, Russia (called Plagiorhegma dubium in Flora of China)
- Jeffersonia lobata Nutt.
- Jeffersonia odorata Raf.
- species in homonymic genus
- Jeffersonia sempervirens Brickell, now called Gelsemium sempervirens (L.) J.St.-Hil
Jeffersonia has had a variety of medical uses. One is hinted at by an archaic common name of Jeffersonia diphylla, Rheumatism root. The roots of both species contain berberine, a known anti-tumor alkaloid. The plant is therefore considered poisonous.
Native Americans use Jeffersonia diphylla for a variety of medicines.
The whole plant was used in early American medicine as an antispasmodic, diuretic, emetic, expectorant and general tonic. The "root" was once also used as an emetic in large doses, and as an expectorant in small doses. Modern medicine does not use this plant.
- Flora of North America: Jeffersonia
- USDA Plants Database: Jeffersonia
- The Plant List, search for Jeffersonia
- Biota of North America Program 2013 county distribution map
- Flora of China Vol. 19 Page 783 鲜黄连 xian huang lian Plagiorhegma dubium Maximowicz
- Tropicos, Jeffersonia Brickell
- Hamel, Paul B. and Mary U. Chiltoskey 1975 Cherokee Plants and Their Uses – A 400 Year History. Sylva, N.C. Herald Publishing Co. (p. 59)
- Herrick, James William 1977 Iroquois Medical Botany. State University of New York, Albany, PhD Thesis (p. 332)
- Plants for a Future Database: J. diphylla
- Plants for a Future Database: J. dubia