Plant Life: Skunk Cabbage

A Smelly Sign of Spring

One of the many signs of spring at the Bloedel Reserve is the blooming of the skunk cabbage (Lysichiton americanus). Beginning in March, well after any snow has disappeared, the yellow bracts that we erroneously think of as flowers begin to emerge from the ground in wet areas. Clasped within these yellow, oval shaped bracts is a spike of tightly packed flowers that don’t look much like flowers at all.

This plant gets its name from the skunky odor it emits when blooming. Cut or damaged foliage also seems to emit this scent. The mildly malodorous flower spike attracts a particular species of rove beetle that serves as a pollinator. The beetles congregate around the flowers and bract to eat pollen and to mate. After pollination, the showy yellow bracts wither and the flower spikes begin to mature and produce seeds. Often the spikes don’t reach maturity because they serve as food for squirrels and other rodents. (Human children also seem very fond of using the spikes as toy clubs.)

One common myth about these curious plants is that the blooms emit heat. In fact, they do not. This myth probably evolved from the fact that members of the closely related genus Symplocarpus do emit heat, possibly as means of melting any snow surrounding the plants as they begin to grow in  late winter.

This Beauty Is a Beast

As the flowers are developing, the plant sends up large leaves in a rosette around the yellow bracts. In fact, the skunk cabbage in boggy area near the boardwalk at Bloedel Reserve can grow quite large — producing  leaves up to three feet long. In the moss garden, skunk cabbage is both loved and hated. Its foliage adds texture and variety to the landscape of green mosses. But it also spreads assertively in wet areas. If not kept in check, skunk cabbage can crowd out mosses and liverworts where the water table is high. Controlling this plant is tricky. The actual base of the stems grows down many inches under ground. Digging out the stems completely would severely disrupt the moss. Instead Bloedel crew members use soil knives or trowels to stab the ground at an angle and sever the plant’s leaves. Performed once or twice a year, this angled pruning keeps the skunk cabbage from taking over.