Teucrium canadense

Germander, Canadian germander, wild germander, wood sage, wild basil

Botany

Germander is native across most of North America and typically grows from late spring to fall, producing flowers midsummer. Flowers of the T. canadense vary in color from a light lavender to pinkish color, growing in spiked terminal clusters on a tall square stem which usually grows to a height of one to three feet(2). Leaves of the germander plant are dark green with a toothed or serrated edge and grow opposite each other, forming a relatively low-growing garden shrub3. Germander grows best in high water conditions with partial shade and moist soil with a medium tolerance for calcium carbonate in the soil. When the plant is present in dense clusters, it can produce a more impressive flower stalk which makes a pretty cut flower or can be used ornamentally as an aromatic, garden border, carpet or ground cover. However, the plant does spread very aggressively on its own in moist conditions by spreading underground rhizomes when left unchecked, so it should be trimmed and cut back periodically to prevent invasiveness(3).

Chemistry

Germander has many active components including glycosides, flavinoids, saponins, furano neoclerodane diterpenoids, and volatile oils as well as tannins and bitter aromatics. The suggested mechanism of action for the diterpenoids (the hepatotoxic-causing component) is oxidation by the cytochrome p450 system into harmful reactive metabolites that bind to proteins, decrease glutathione levels, and cause massive cell injury especially in the liver. This mechanism is similar to acetaminophen overdose, and the effects worsen with increasing doses(6).

Fun Fact

An interesting fact about T. canadense is that they attract butterflies when in bloom and the flower itself is shaped as the perfect landing strip for the insects to sit and drink the nectar. The top lip of the flower is a short, vertical flap while the bottom lip is longer and protrudes horizontally up to a half-inch in length(2).

History

Uses/Pharmacology

The first known medicinal use for germander was by Native Americans that dried and ground the leaves to make a tea to induce sweating and urination(4). All aerial parts of the plant can also be used as an antiseptic poultice wound dressing or into a tincture gargle to treat bad breath and kill germs in the mouth(4). The plant has recently come to the attention of the public as an extract tea marketed for use as a weight loss aid as well as for management of diabetes and high cholesterol(6).

Dosing/Recipes

Contraindications/Interactions/Adverse Reactions

Current guidelines on botanical safety, however, place germander in safety class 3. This means the plant is considered unsafe and should only be used under the supervision of an expert qualified in appropriate use of the substance due to reported hepatotoxicity, hepatitis, and even death from several cases of incorrect use of the plant6,5. External use as an antiseptic would dressing or antiseptic gargle may still be a safer option, as long as no part of the plant is ingested.

References Cited

1. Teucrium canadense. United States Department of Agriculture: Plants Database. Accessed 19 Feb 2012. Available online from .

2. Teucrium canadense. Lady Bird Johnson Wildflower Center. The University of Texas at Austin, 2012. Accessed 9 March 2012. Available online from .

3. Hilty, John. Teucrium canadense. Illinois Wildflowers, 2012. Accessed Available online from .

4. Teucreium canadense. Native Wildflowers and Prairie Plants. Ion Exchange, Inc., 2012. Accessed 14 April 20112. Available online from .

5. McGuffin M, Hobbs C, Upton R, Goldberg A. American Herbal Products Association’s Botanical Safety Handbook. CRC Press, LLC; 1997.

6. Germander. United States National Library of Medicine, 2012. Accessed 14 April 2012. Available online from