Wednesday, April 2, 2014

Skunk Cabbage

Spathe framed by unfurling leaves. Click on photo to enlarge.
Two signs of spring occur in April: the still-furled skunk cabbage leaves are roughly hand-tall, and young men start to drive their convertibles with the top down. Both of these spring-signifiers are pushing the season. Compared to skunk cabbages, all other woodland plants are just beginning to show leaf buds. And women will not yet be driving convertibles. Let’s focus today on the botanical story and leave the human mystery to the social psychologists.

The Latinate nomenclature for skunk cabbage, Symplocarpus foetidus, makes clear this plant is fetid, i.e., stinks. Tearing or crushing leaves will release a sulfurous smell akin to whiff of skunk, combined with notes of rotten eggs, garlic, and rotting flesh.

Skunk cabbage prefers boggy woodlands. In mid-summer these regions will be dry and in deep shade, but at the front end of spring they are wet from snow-melt and sun-lit. During April the leaves are unfurling, growing, and will in time form plants that will be 2 to 4 feet across. Each stalk ends in one leaf. At full growth the leaves superficially resemble the open leaves surrounding a head of cabbage – hence the name. By mid-July, when the trees are in full-leaf, skunk cabbage leaves are already beginning to decay. By mid-August all that is left are root clusters deep under the soil’s surface, waiting for next year.

The unfurling of green leaves is actually a skunk cabbage’s second act. Weeks earlier, a specialized leaf called a spathe emerged from the ground. Spathes are not green. Instead, their colors are positively Lovecraftian: eggplant-like purples, wine-dark maroons, streaked or mottled with yellowish green. Size-wise, spathes are 3 to 6 inches tall. Shape-wise, think of a somewhat stretched Hershey’s Kiss, two to three inches across at the base, with the top twisted and/or tipped to one side. Inside the spathe, and accessible to the outside by only a narrow opening, a stalk forms with a flower head atop, called a spadix. Carrion-feeding flies enticed by the rotting smell enter the spathe-space, pick up pollen in the process of exploring the spadix, then depart to visit other spathes, completing the fertilization process.

Skunk cabbage melted a hole in the snow
Skunk cabbages have one trick shared with just a few other plant species – heat generation. The air space inside the spathe will be 15 to 30 degrees higher than the outside temperatures. Heat protects the flower from freezing at night. Furthermore, the combination of warmth and odor attracts the flies that will be fooled into the task of fertilization.

Patches of skunk cabbage are easily viewed from the Assabet River Walk trail. This marked trail starts from Concord Street, one-third of a mile east of Route 27, on the right. There is a sign. Cars can be parked across Concord, on Hird Street. The trail descends 60 feet over a half-mile length, to the bank of the Assabet River, and would be considered mildly difficult for an experienced mountain biker. The skunk cabbage patches are about a quarter mile in, to the right (downhill) side of the trail. Closer to the center of town, skunk cabbage inhabits the wet area at the back of Carbone Park, across Concord Street from ArtSpace/Acme Theatre.

This column was first published in the Beacon-Villager in April 2010. A recent hike in the woods confirmed that skunk cabbage spathes are again rising up (leaves to follow), so time to go a-walking.  

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