Fuki
Petasites japonicus
Washington State Classification
Monitor List
This plant is on the monitor list - it is not a listed noxious weed in Washington.
Quick Reference
Identification
Growth Habit
A perennial herbaceous plant with creeping rhizomes that sends up flowering stems first, followed by large, rounded basal leaves on long stalks (petioles).
Leaves
Basal leaves with long petioles grow directly from the rhizomes. Leaf blades rounded to round-kidney shaped, ranging in width up to 5 feet (1.5 m) wide for the variety giganteus. Blades have toothed margins and are sometimes quite hairy on undersides (white-woolly) or almost hairless, while upper leaf surface is green with some hairs. Flower stems have alternate, leaf-like bracts that are narrow and have parallel veins.
Flowers
Flower stalks grow from rhizome, up to 1.5 feet tall, with many flowerheads of whitish disk flowers. Plants in the Petasites genus are typically dioecious, with male and female flowers on separate plants.
Fruit & Seeds
Achenes (a small, dry one-seeded fruit), about 3.5 mm long, hairless, with 5 to 10 ribs on surface, with a tuft of bristles about 12 mm long on its end.
Impact
This plant is on the monitor list - it is not a listed noxious weed in Washington. Please contact Heidi Steinbach via hsteinbach@masoncountywa.gov to report locations of plants growing outside of ornamental plantings.
Ecology & Spread
Habitat
Roadsides, ditches, along creeks and streams, woodlands, wet areas - on moist ground.
Spread Mechanisms
Reproduction
Rhyzome, seed
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