Many native British Columbia alpine plants such as Mountain Sorrell (Oxyria digyna) connect our flora to the tundra and high mountains of Asia. In the lowlands there are fewer species in common between these two continents. Among these is one of the most remarkable plants in our province, the skunk cabbage (Lysichiton americanus), known also as Yellow Arum and by the more evocative names of Swamp Lantern and Skeena Lily. This robust perennial forms modest to luxurious clumps of leaves reminiscent of the tropics. It is best known for the large yellow blooms that light up damp forest corners in the spring time.
Skunk Cabbage grows from a short thick underground root-stem (rhizome). Numerous large white roots anchor the plant firmly in the muck. Huge egg- to lance-shaped leaves arise vertically from the rhizome. The leaves are usually shiny, bright green and waxy, but some populations are marked by dark blotches. The short leaf stalk is thick and succulent. It widens to a leaf blade from 10 -70 cm (4-28”) wide and 30 -150 cm (12-60”) long. In the lush swamps of the Fraser River the leaf clumps reach nearly 1.5 m (60”) tall. Leaves unfurl in spring and remain up until late summer to fall when they flop onto the ground and die back.
Before the leaves even emerge the presence of skunk cabbage is announced by the striking yellow flowerhead. As early as the beginning of March the stiff flower bud punches through the soil surface and then expands to reveal a hood-like form surrounding a long stiff central stalk. The flowerhead reaches from 30 to 50 cm (12-20”) high and is detectable well before you see it because of its skunky odour. The sheathing cowl is called a spathe and, as is typical of many of the species in the Arum family (Araceae), is formed from a modified leaf. The flowers are jammed cheek to jowl along the central stalk called a spadix. Each flower is scarcely half a centimetre wide with four stamens and a central pistil with two ovaries. The skunky scent attracts pollinating flies and midges. Flowers persist well into the spring and in cool climates into the summer whereupon they decompose into a white pulpy mush and reveal brown oval seeds.
Skunk Cabbage is widespread in the coastal zone of northwest North America from the Aleutian Islands of Alaska to northern California. Scattered populations also occur inland of the Coast Mountains from Washington State to the Peace River country of BC. Typical habitats include bogs and bog edges, swamps dominated by deciduous and coniferous trees, sloughs, ditches and lakeshores. Magnificent stands of skunk cabbage crowd the channels and back swamps of the Fraser River in the Lower Mainland of the province. The species loves wet places both shaded and sunny. The largest plants inhabit shady sites along streams, but flowering plants are most abundant in open settings.
British Columbia First Nations used the leaves to wrap food, much in the way we use wax paper today. Leaves were also used to line berry baskets and steaming pits. Ancient stories recall the importance of the roots, many times cooked and washed, as famine food before the coming of spring salmon. The leaves should never be chewed or eaten because they contain highly irritating calcium oxalate crystals. Leaf and root poultices were once widely used to treat conditions such as swellings, boils, burns and sores.
A sister species of our Skunk cabbage, Asian Skunk Cabbage (Lysichiton camtschatcensis) graces the wetlands of Pacific east Asia from the Kamchatka Peninsula to northern Japan. It is also known as White Skunk Cabbage because of the flower colour. Asian Skunk Cabbage has been considered the same species as ours by some botanists, but generally does not grow quite as tall. Like our plants the Asian Skunk Cabbages often emit a strong, somewhat unpleasant, odour; however, some populations reputedly smell sweet.
Both Asian and North American species have been widely adopted as garden plants for their early and striking bloom and lush leaves. Pieces of the rhizome with a terminal bud can be dug up in the fall to early winter and transplanted into suitably damp sites in the garden. For propagation from seeds, plant them in organic soil as soon as the fruits ripen. Immerse the pot or tray in shallow standing water or keep very moist and leave over the winter for spring germination. Transplant individual seedlings into pots for growing on until they are large enough to set out in the garden.
Although this species behaves itself well in its native territory, our skunk cabbage has proven to be a serious invader in northwest Europe. Having escaped their gardens it now clogs streams and other water ways in Scotland and England and is subject to eradication efforts.
As a final note, our native skunk cabbage connects us not only across the Pacific but also to the tropical island of Sumatra in Indonesia. Sumatra is the native home of the Titan arum (Amorphophallus titanum) also of the Arum family, that produces the largest unbranched flower head in the world, up to 3.7 m (12‘) tall. This botanical monster also has that skunky “fragrance” . Our species can only be described as slightly scented or evenly pleasant in comparison. To see titan arum (without the fragrance) connect to titanarum.cals.cornell.edu/video.
Richard Hedba would like to acknowledge Ken Marr and Erica Wheeler who provided useful advice and review of this article.