Skunk Cabbage—
The First Flowers of Spring
By Carol Gracie

In late February or early March, our first spring wildflowers will be in bloom. You will have to stoop down and perhaps get your feet wet to appreciate them fully, but it will be worth it.

Skunk cabbage is a member of the Araceae, or Jack-in-the-pulpit family, a family of up to 3,000 species, most of which are found in the New World tropics. You may be familiar with some of its tropical relatives as house plants, garden annuals, or cut flowers: Philodendron, Monstera (Swisscheese plant), Caladium, and Anthurium (flamingo flower) among them. The family also includes a species with the world’s largest inflorescence, Amorphophallus titanum, which can be as tall as a person; and a small, floating aquatic plant, Pistia stratiotes (water-lettuce) that chokes waterways in the south and has a diminutive version of the same floral structure. The term inflorescence refers to a grouping of flowers, rather than an individual flower. Plants in the Araceae bear their tiny flowers on a structure called the spadix, which in the case of skunk cabbage is more or less spherical. The spadix is surrounded by a modified leaf called a spathe. This combination of characteristics makes the family easy to recognize worldwide.

Skunk Cabbage Leaves

Skunk Cabbage Swamp

Both the common name and the scientific name, Symplocarpus foetidus, make reference to the fetid odor given off by the plant if it is cut or bruised—not really skunk-like, but definitely unpleasant. However, if you step carefully into the swamp so as not to damage the plants and kneel down to put your nose close to the opening of the spadix, you may detect a faint, floral aroma if the flowers are in bloom. On warm days in late winter, these early blooming swamp dwellers rely on visits by flesh flies or honey bees for pollination. The insects are attracted by the color of the plants, the aroma of the flowers, and/or the warmth contained within the spathes. Many members of the Araceae, including skunk cabbage, are able to generate heat in the spadix through a somewhat unusual means of respiration (the use of oxygen to burn carbohydrates for fuel). The difference between the spadix and the ambient air temperature may be as much as 25ºC under optimal conditions (slightly above freezing) and can literally melt the ice or snow surrounding the plant. Heat production coincides with the opening of the flowers. The heat helps to volatilize the aroma of the flowers to attract bees seeking an early source of pollen or flesh flies looking for a place to lay their eggs. Both insects benefit from the heated refuge within the spathe to warm their flight muscles, and both come in contact with the stamens and pistils of the flowers, inadvertently transferring the pollen from one to the other. The success of this rather chancy method of pollination is limited, particularly if bad weather occurs at the time of bloom and prevents the insects from flying. Thus, relatively few plants produce mature fruit.

Skunk Cabbage Spathes

While you’re on your knees smelling the flowers, take the opportunity to examine them—a hand lens (or reversed binoculars) will help. Each tiny flower has both male (four stamens) and female parts (one pistil), though they are viable at different times. It’s therefore possible for the later blooming, lower flowers to be pollinated by pollen from the earlier blooming flowers at the top of the spadix. The flowers have no petals, but four tiny sepals surround the reproductive parts.

Once flowering has finished, the lovely, sculptural green to maroon spathes begin to wither and an adjacent green cylinder will push its way above the soil and begin to unfurl the large, bright green leaves that carpet the swamps in May. Their luxuriant growth evokes the sense of renewal that comes with spring. Individual plants are slow growing, producing just a single leaf the first year, two the second, and so on. It may take seven years or more until they are robust enough to produce an inflorescence.

The large leaves function as efficient solar collectors allowing the plants to carry on photosynthesis in the limited light of the swamp. The leaves are rarely eaten by herbivores as they contain calcium oxalate crystals that burn the mouth, but I have witnessed Canada Geese eagerly feeding on them. By late summer, the leaves are gone, but you may find the fruit if you look carefully. Fruits are soft, dark orbs, 2-3" in diameter, formed by the fusion of many ovaries (Symplocarpus means compound fruit); they somewhat resemble a small hand grenade. The hard, dark seeds germinate in the damp soil beneath the parent plant or are sometimes transported by squirrels. The new, young spathes may emerge as early as autumn or into early January, but most appear in mid-February. The strong, contractile roots of skunk cabbage help to anchor the plants firmly in the wet soil and store nutrients for their late winter growth when the cycle begins again. The plants are thought to be very long lived.

See Carol Gracie's Scenes of the Seasons - Spring
and
Carol Gracie's Hepatica, The Other First Flower of Spring

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