Lysichitum americanum [sic] is considered a synonym

americanus – native region of the species (America)

Native range: Pacific Northwest (of North America)

Leaves:

• simple
• basal
• oblong-ovate
• fleshy
• entire margins
• short-stalked leaves are largest of any native plant in PNW (30–150 cm. long (12–60”)

Flowers:

• on thick spadex (spike-like inflorescence)
• surrounded by large, yellow spathe (leaf-like bract) up to 2 dm long
• yellowish-green tiny flowers on spadex
• protogynous, i.e., spadix emerges from the spathe as a pistillate inflorescence and transitions to a pollen-producing male phase several days later
• female flowers are lower on the spadix and male flowers are above.

Fruit:

• berry-like
• greenish
• 1–2 seeded
• embedded in white pulpy axis of spadix (~2” long in aggregate)

Other characteristics:

• one of the first plants to bloom in late winter/early spring
• monocot
• slow growing, but may be up to 80 years-old

Relevant info:

• the only other species in this genus occurs in Japan and the Russian Far East
• leaves used by Native Americans in PNW for lining berry baskets, berry-drying racks and steaming pits
• because of attractive yellow spathe, species was introduced through the gardening trade to England in 1901
• seen in the wild by 1947 and is now considered invasive in Europe, where the wetlands it occupies are themselves diminished
• naturalized populations in the Netherlands have been targeted for eradication
• listed as an “invasive alien species of concern” in the European Union in 2016

Ecology & Adaptations:

• native to Alaska south to California
• in Washington, both sides of the Cascades
• found in wet often wooded areas (swamps, fens, muskeg, wet forest, mucky seepage areas, wet meadows) from sea level to mid-elevations in the mountains
• pollination:
  • distinctive odor is emitted when blooming
  • combination of skunk, carrion (dead animal flesh) and garlic odors attracts pollinators, such as scavenging flies, midges and beetles that may feed on carrion
  • the beetle Pelecomalius testaceum is the principal pollinator and feeds on the pollen and uses the spadex as a mating site
    • recent research indicates that this beetle specifically responds electrophysiologically and behaviorally to indole (compound with 2 carbon rings) in the flowers, without any additional association with carrion or feces, indicating a close association with the plant species
• seed dispersal:
  • via water downstream
  • eaten by squirrels and bears and possibly birds, which may disperse seeds upstream
• vegetative reproduction – spreads via rhizomes up to 30 cm long
• herbivore defense:
  • leaves contain calcium oxalate rhaphides (needle-shaped crystals with sharp tips) that are loaded in specialized, explosive ejector cells on the edge of leaves and surface of stems
  • under pressure, such as crushing of the plant when chewed by an animal, the needle-like crystals are ejected and penetrate surrounding tissue, resulting in intense irritation, discomfort, histamine release, numbness, paralysis of tongue, and trouble swallowing
• shade tolerance:
  • early emergence and extremely large leaf surface captures maximum light
  • tall, erect leaves enable plant to reach above surrounding ground cover species
• adapted to wetlands:
  • seed dispersal by water
  • vegetative reproduction decreases reliance on germinating seeds that need oxygen
• competition – large leaves emerge early in growing season and capture more light than competing neighbors in the ground cover