Japanese chaff-flower (Achyranthes japonica)

Synonyms: Achyranthes bidentata var. japonica

Common Names: Japonica

Description: First discovered in the United States in eastern Kentucky in the early 1980s.

Habit: Herbaceous perennial that can form dense colonies and grow up to 6.5 feet tall.

Leaves: Simple, opposite, ovate-elliptic shaped. Leaf margins are entire and slightly wavy and entire plant is slightly pubescent.

Stems: Slightly pubescent or glabrous, erect and growing up to 6.5 feet in height.

Flowers: Occur on tight clusters of erect spikes, blooming in late summer. Tiny flowers lack petals and they form at right angles from the spike.

Fruit and seeds: Fruits lay flat against elongated spikes that have a pair of stiff bracts that aid in attachment to cloths, shoes and animal fur. Seed maturation occurs in early fall.

Habitat: Native to eastern Asia. Found in forests, riparian areas, open grasslands, and disturbed areas such as ditches and field edges.

Reproduction: By seed or vegetative by vigorous rhizomes.

Similar species: American lop seed (Phryma leptostachya), a common perennial forb of Wisconsin, especially when in fruit. American lop-seed can be best distinguished from Japanese chaff flower by its toothed leaves that come to an elongated point at the tip.

Monitoring and rapid response: Hand pull small infestations or newly germinated plants. Continuous monitoring is required due to vigorous root system. Remove plants before seed-set. Herbicide treatments may need to be conducted every 2 weeks with the use of glyphosate or triclopyr.

Credits: The information provided in this factsheet was gathered from the Wisconsin Department of Natural Resources and the River to River Cooperative Weed Management Area Invasive Species Alert.

Individual species images that appear with a number in a black box are courtesy of the Bugwood.org network (http://www.invasive.org).Individual photo author credits may not be included due to the small display size of the images and subsequent difficulty of reading the provided text. All other images appear courtesy of Google (http://images.google.com).

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