Friday, March 22, 2002
Biodiversity Corner Skunk Cabbage
When and where found: In many of the swampy parts of town. This specimen was photographed at Towle Field on March 14. Some were emerging the first weekend in March and many are now several inches tall and flowering.
Distinguishing characteristics: Despite their name, skunk cabbages are more likely to be found by sight than smell. If you see a reddish-brown cowl-shaped form sometimes streaked with green coming up out of a swamp, beside a stream or even in a shallow slow-moving stream, it is probably a skunk cabbage. If you peek inside the hood, called a spathe, you will see a knob about the size of a golf ball. It is called a spadix and at this time of year is covered with tiny yellow flowers. The flowers bloom and are pollinated entirely within the cover of the spathe. As the spathe withers, the large vaguely cabbage-like leaves appear and unfurl. They have an unpleasant smell when crushed. Do not put them in the cole slaw.
Friends and relations: Skunk cabbage is part of the Arum family of which a more glamorous member is the Jack-in-the-pulpit. (The pulpit is the spathe and Jack is the spadix.) Another relative, the Yellow Skunk Cabbage (Lysichitum americanum), is native in the western U.S. Its striking golden-yellow spathe has ornamental value for wetland gardens. It will grow in the eastern U.S.
Strange family behavior: The skunk cabbage is one of the members of the Arum family with the unusual ability to generate heat and regulate its temperature as a warm-blooded animal might.
For a period of up to two weeks the spadix can generate enough heat to raise its temperature as much as 45 degrees Fahrenheit above the ambient temperature. When there is snow or ice cover, skunk cabbages can melt a hole through which to emerge. The heat plays a role in releasing compounds that attract pollinating insects, mainly flies.
References: Common Wild Flowers of the Northeastern United States, published by the New York Botanical Garden. Also, there is an excellent paper by Craig Holdrege on the web site of The Nature Institute at http://www.netfuture.org/ni/ic/ic4/skunkcabbage.html.
Submissions for the Biodiversity Corner are encouraged from everyone. The only requirements are that the species exists in the wild and was seen in Carlisle. You can write the column yourself or tell me what you saw and I will write it. I can also help with drawings and photos. Emerge from your cocoon, spring into action, and send a note to Kay Fairweather at 392 School Street, Carlisle MA 01741 or firstname.lastname@example.org.
© 2002 The Carlisle Mosquito