Wild ginger (Asarum canadense*) of the Dutchman’s-pipe (Aristolochiaceae) family is a low-growing woodland spring ephemeral. It occurs throughout the eastern U.S. from Louisiana and Oklahoma to North Dakota thence eastward to the Atlantic Coast, except Florida. In Arkansas, it occurs throughout the Interior Highlands (Ozarks, Arkansas Valley, and Ouachitas) as well as on Crowley’s Ridge. The genus name originates from an ancient Greek name, asaron, of uncertain derivation. The specific epithet refers to the plant’s occurrence in Canada. Other common names include Canada wild ginger and southern snakeroot. Preferred habitat is shady deciduous woodlands with rich, mesic soils found in uplands, floodplains and rocky slopes.
Plants have shallow, branching, slow-growing underground stems (rhizomes) that are round in cross-section and smooth except for widely spaced nodes. Long, slender and down-trending roots, with attached fibrous rootlets, randomly grow from underside of rhizomes. Although rhizomes are slow-growing, thick colonies may form. Rhizomes of wild ginger have the taste and smell of culinary ginger (Zingiber officinale), thus the common names, but is otherwise unrelated to this Old World tropical plant.
Photo 1: Near-surface rhizomes are smooth and heavily rooted. New growth originates at terminal and lateral buds.
New vegetative growth originates from ascending buds at tips of main rhizomes and shorter lateral rhizomes that originate at nodes. Each vegetative bud produces a short underground ascending stem, bearing two alternate bracts, and terminating with one or two leaves. When two leaves are present, a single flower may occur between petiole bases. Additional growth of the rhizomes also originates at rhizome tips from separate buds.
Leaves are orbicular, broader than long, deeply and openly cordate, with two large half-circular lobes. Leaves, to more than 4 inches long and 6 inches wide, have an upper surface that is medium to dark shiny green while lower surface is a lighter green. Upper and lower surfaces have very short hirsute pubescence with hairs of lower surface being mainly along veins. Leaf margins are entire with short dense pubescence (ciliate). Leaf tips are obtuse to rounded. Principal venation of upper surface, consisting of a straight midvein and three lateral veins to either side, is depressed. Midvein extends from petiole to blade tip while the laterals extend from corners of the sinus toward leaf margins, in dendritic fashion. Blade surface, including the large basal lobes, is mostly planar with central area becoming sunken toward the petiole. Leaves are thin, but appear leathery, due to blade surface between veins being raised. The petioles, slender and grooved, are up to 11 inches long and are covered with long, fine, twisty to woolly pubescence.
Photo 2: Leaves, occurring singly or in pairs, are orbicular with deep, broadly-open sinuses at the bases.
Flowers, appearing in early spring, are on short (to 1 inch) peduncles and are ascending to resting on the ground. Flowers, to 1 inch long, have a thick-skinned, six-sided, bell-shaped (campanulate) calyx bearing three spreading to reflexed, triangular to long-acuminate, petal-like lobes. (A true corolla is absent.) When lobes are triangular, apexes typically terminate with abrupt, short, oblong points. Flower color is variable, but generally the exterior of the calyx cup is a light yellowish brown below, becoming a light to dark reddish brown above and across outside and inside of lobes. Reproductive organs are exposed when calyx lobes recurve to yield an inch-wide flower. Interior color of calyx varies from being entirely white to a yellowish green. A yellowish green calyx may have purple, geometric, six-sided markings that encircle the lower portion of the cup. Peduncles are densely covered with long, woolly, white to purplish pubescence that extends over calyx and exterior of lobes.
Photo 3: Single flowers grow from between pairs of leaves. Note pubescence on leaf blades, petioles and calyx. Leaf in upper right corner is a violet. Photo taken April 7th.
Flowers have 12 sturdy stamens that encircle a stout central column of six upright styles. Stamens and styles are reddish to purplish. Stamens are attached to top of the inferior ovary. Straight, narrow filaments bear anthers with tiny, pointed, sterile extensions, like clawed tips, between the pollen sacs. The upper portions of stamens are initially bent outward, but with anthesis, stamens become upright and the outer sides of anthers split open to release yellow pollen. At anthesis, clawed tips are pressed back toward flower center and down onto style column. Flowers have a scent similar to rotting fruit.
Photo 4: The twelve stamens have released their yellow pollen, some of which can be seen on the six stigmas. Six of the now-barren stamens are positioned between pistils (see star pattern) while other six stamens are positioned across stigmas.
Photo 5: After anthesis, stamens and styles shrink and colors fade. Photo taken April 20th.
With fertilization, the fruit capsule enlarges and then splits at the top across its six chambers while remnants of calyx lobes, stamens and styles remain. Stacked, dark brown, smooth, rounded seeds, with dark brown spongy-looking elaiosomes attached at one side, become dislodged as the fruit capsule dries. These elaiosomes, a food source for ants, are carried, with seeds attached, into ant colonies. After removal of elaiosomes, seeds are discarded by the ants. Thus, ants obtain food and the wild ginger has its seeds dispersed (an example of myrmecochory).
Photo 6: Fruit capsule has split to discharge mature, smooth, brown seeds with attached elaiosomes. Photo taken May 19th.
In a shady woodland garden, wild ginger with its attractive leaves, would be an easily maintained ground cover for borders or an infill between larger plants. This species is not aggressive, does not need tending, and is not eaten by herbivores. Leaves are known to cause skin irritation for some people. Rhizomes should not be used for culinary purposes, as they have been found to contain carcinogenic compounds.
- Several varieties of wild ginger have been named by various authorities based on shape and length of calyx lobes. Some authorities, however, consider the variations too numerous and geographically intermixed for formal recognition.
Article and photographs by ANPS member Sid Vogelpohl