Woodland Plants: Wild Ginger By Darcie McKelvey

Rooting out burdock along the edges of the forest at the end of April, I happened to see the wrapped and silver-coloured wild ginger leaves (Asarum canadense) poking up through the leaves. How unappreciated this common woodland herb is!  Gardening catalogues refer to it as “an attractive groundcover.”  It would get rave reviews if its flower was not so modest and inconspicuously located.

“Asarum” comes from the Greek word “asaron,” referring to a plant found in ancient Greek times (Asarum europaeum), and “canadense” means “of Canada.”  Our Canadian ginger is one of around 70 species of Asarum found worldwide, but the only one native to Canada.

Asarum canadense has wide, heart-shaped leaves, which are generally 8 to 12 cm across, and not as long as they are wide. The leaves, which are smooth on top and hairy underneath, are usually grouped in twos. They are supported by tall, slender, hairy stalks, which project up from rhizomes just under the ground. The rhizomes have a ginger-like aroma and taste and were used by natives to flavour their foods. The rhizomes spread, a key factor in being considered an attractive groundcover. The leaves are a velvety green and they do not disappear in summer, as many of the spring ephemerals do.

The single, small flower (2 cm wide and 2-5 cm long) of Asarum canadense is found at the base of the leaf stalks underneath the leaves– it is right on the ground and you would not see it unless you were a crawling insect or specifically looking for it. The colour of the flower is an understated maroon-brown. It is urn-shaped, flaring into three sharp-pointed sepals, an arresting configuration.

I have read, but personally have not noticed, that the smell of the flowers is foul, mimicking carrion. This attracts flies, particularly carrion-eating flies. Flowers are also pollinated by beetles. Each calyx contains several seeds that fall close to the plant or are dispersed by ants. Similar to bloodroot and trillium seeds, wild ginger seeds have an elaiosome or protuberance from the seed coat, which is filled with an oily fluid that ants find irresistible. The ants consume the elaiosome and discard the seed in ant tunnels, where they are safe from other predation.

Asarum seeds are seldom offered by seed exchanges, probably because the flowers are out of sight and seeds are difficult to locate, unless your timing is perfect. To be successful in germination, the seeds should be sown immediately in a shaded outdoor seedbed.  The seeds are hydrophilic and must not be allowed to dry out. Germination will not occur until the seeds go through a warm period (the remainder of the summer) and then a cold period (the following winter). Propagation by division of the rhizome during dormancy is probably easier than growing Asarum canadense from seed.

Wild ginger is found from Manitoba to New Brunswick, north into coniferous woodland and south to North Carolina. It is common in humus-rich woods, with soils that remain moist but not wet. It will grow in either partial or full shade and is not fussy about the acidity of soil. We are blessed to have such an accommodating plant in abundance in our woodlots.

References

Jim Dyer, Pollinator Watch

Britton and Brown, An Illustrated Flora of the Northern United States and Canada, Volume I

This article was featured in a past edition of the S&W Report, the newsletter of the Ontario Woodlot Association. 

© Ontario Woodlot Association, 2010