By LESLIE BISHOP, guest columnist
As folks are scouring the forest floor for morel mushrooms, I also search, but see only flowers.
One flowering plant in particular catches my eye because it looks more like a fungus than a plant; it even shares the golden brown color of morels.
Cancer root (also called squawroot and bear corn) pokes up through the leaf litter, but does not turn green like most plants. In fact, it is devoid of chlorophyll. Before blooming, the stalks look like small pinecones, and thus it makes sense that botanists gave the plant the scientific name Conopholis americanus (from Greek “conos” meaning cone and “pholis” meaning scale).
Similar to the lifestyle of soil fungi, cancer root relies on tree roots for vital carbohydrates produced in the tree’s leaves. But the similarity stops there. The soil fungi’s relationship with trees is mutualistic: the fungi give back to the tree roots services like increased water absorption and nutrients (nitrogen and phosphate).
[sc:text-divider text-divider-title=”Story continues below gallery” ]In contrast, cancer root’s relationship to trees is parasitic: the tree gets nothing in return. Cancer root penetrates the roots of oaks specifically, with a preference for red oak. But unlike in many other parasitic relationships, up to now biologists have not found significant negative effects of cancer root on the health of host trees.
The pinecone-shaped structure we see in late spring bears about 70 tiny, cream-colored tubular flowers. Only the flowering structures appear above ground; the plant body, or tubercle, is entirely subterranean. One tubercle can produce, on average, three to five flowering stalks.
Little is known about the pollination process. Some say that bumblebees will visit the flowers, and others say flies. But one study showed that flowers from which insects were excluded produced seeds at the same rate as flowers exposed to insects. Thus, self-pollination seems to be the main mode of reproduction.
Despite its parasitic nature, this odd plant serves an important ecological role. Several studies in the southern Appalachian Mountains have shown the importance of cancer root in the diet of black bears. The nutrients in the seeds of the plant are of significant value to lactating female bears. In fact, cancer root is considered one of the three most important “bear foods,” in addition to acorns and blueberries. Thus, another common name for this species is bear corn.
In our neck of the woods, we don’t have bears (yet), but cancer root stalks are also relished by white-tailed deer. In a study on the spring diet of white-tailed deer, biologists found that cancer root is second in importance to the flowers of tulip trees.
Plant common names often cause confusion because the same species can have very different common names in different places. Usually, common names merely reflect the observations of people living with the plants, whereas the scientific name is universally accepted. Some say cancer root got its name not for the treatment of cancer, but for its odd growth form.
Others call the plant squawroot. Along with several other herbaceous plants, early American colonists observed indigenous women collecting plants for medicinal purposes and called all the plants squaw roots for treating female ailments.
Today the term “squaw” is considered a derogatory reference to women and to Native Americans. The currently most accepted names for the plant are cancer root and bear corn.
Under any name, this curious plant is fascinating. And the only way to appreciate its bizarre beauty is to get out in the woods, search for the stalks, and get a close look. Like morels, cancer root is one of the treasures of our Indiana forests!
Leslie Bishop is a Brown County resident and retired biology professor from Earlham College. She can be reached through the newspaper at [email protected].
