Species of the Month: Skunk Cabbage
Skunk Cabbage (Symplocarpus foetidus) is among Norfolk County’s earliest blooming wildflowers. It is a member of Araceae (Arum) family, which also includes Jack-in-the-Pulpit (Arisaema triphyllum), Bog Arum (Calla palustris), and Arrow Arum (Peltandra virginica). The name Skunk Cabbage refers to the unpleasant odor created by crushed foliage, and to the cabbage-like appearance of Skunk Cabbage leaves. Skunk Cabbage occurs only in wet areas, such as swamps, riparian areas, bogs, and along the edges of creeks and streams. Often a dominant species, Skunk Cabbage typically occurs in large clusters, which are most noticeable in mid-spring, after the foliage has fully emerged.
[Photo: Skunk Cabbage in the understory of a deciduous swamp, May 2023]
Skunk Cabbage flowers appear in mid-March, but in warmer years, they can appear as early as February. The flowers are pyramidal and burgundy, with small green patches distributed throughout. They appear at the base of each Skunk Cabbage plant, and last for around 4 weeks. Each flower (as in many Araceae species) consists of a spadix (a central stalk containing individual flowers), surrounded by a spathe (a modified leaf, usually colorful like a large petal). Additionally, Skunk Cabbage flowers have the unique ability to melt accumulated snowpack, elevating temperatures between 15-35 degrees above air temperature. Skunk Cabbage flowers often “peak out” of the snow. This phenomena is most typically observed in late February and early March, where average daytime highs are at or just above the freezing point.
Skunk Cabbage flowers emit an unpleasant odor, which attracts their main pollinators – flies and carrion beetles. They are also an early food source for introduced European honeybees, which are attracted to the pollen. Unlike the flies and carrion beetles, the honeybees are not effective pollinators of Skunk Cabbage.
[Photo: Skunk Cabbage foliage, May 2021]
In April, the green cabbage-like foliage quickly emerges. They are often observed alongside Marsh Marigolds (Caltha palustris), the latter species generates brilliant displays with its yellow flowers. By Mid-May, the foliage reaches its full size (~60 cm long and ~35 cm wide). The large leaves of Skunk Cabbage are well-adapted to the heavy shade of the forest understory (physiological adaptations towards larger leaves is observed in many understory plants). Skunk cabbage plants will retain their foliage until around August, after which the plant begins to decline. Most plants are completely defoliated by September. Skunk Cabbage is usually replaced by other swamp plants, such as Wood Nettle (Laportea canadensis), Jewelweed (Impatiens sp.) and Water Hemlock (Cicuta maculata), all of which bloom in late summer.
Written By:
Matthew Palarchio, Honour’s BSc in Environmental Science candidate, Western University
