Thursday, 10 May 2012

Asarum


Asarum is a genus of low-growing herbs distributed across the temperate zones of the northern hemisphere, with most species in East Asia (China, Japan and Vietnam) and North America, and one species in Europe. Biogeographically, Asarum originated in Asia

They have characteristic kidney-shaped leaves, growing from creeping rhizomes, and bear small, axillary brown or reddish flowers.

The plant is called wild ginger because the rhizome tastes and smells similar to ginger root, but the two are not particularly related. The root can be used as a spice, but is a potent diuretic. Asarum canadense and other species in the genus contain the nephrotoxic rodent carcinogen aristolochic acid, which the FDA warns against consuming. The birthwort family also contains the genus Aristolochia, known for carcinogens.

Wild ginger favors moist, shaded sites with humus-rich soil. The deciduous, heart-shaped leaves are opposite, and borne from the rhizome which lies just under the soil surface. Two leaves emerge each year from the growing tip. The curious jug-shaped flowers, which give the plant an alternate name, little jug, are borne singly in Spring between the leaf bases.

Wild ginger can easily be grown in a shade garden, and makes an attractive groundcover.