Japanese hop (Humulus japonicus)

Japanese hop Synonyms: Humulus scandens

Common Names: Japanese hops

Description: Introduced to North America as an ornamental. Can be recognized by its distinctive leaves and long petioles throughout the growing season.

Habit: Annual vine, grows from 0.5-2.5 m (1.5-8 ft) in length, weedy, herbaceous; stems rough.

Leaves: Opposite, 2-4 in in length; deeply divided into 5 distinct palmate lobes with separate margins; rough with hooked hairs.

Stems: Rough with hooked hairs that aid in twining.

Flowers: Dull green in color, 5 petals that are arranged in up to 3/4 in spikes, 2 in long; blooms July through October.

Fruit and seeds: Achenes yellow-brown, ovoid-orbicular, inflated to lenticular.

Habitat: Native to Eastern Asia. Found in disturbed sites including roadsides, old fields, and river and stream banks.

Reproduction: By seeds dispersed by wind and moving water.

Similar species: Native common hop (Humulus lupulus) looks very much like Japanese hop but is usually 3 lobed or unlobed; native bur cucumber (Sicyos angulatus) lacks prickles, has tendrils and the leaves have much less pronounced lobes.

Monitoring and rapid response: Hand-pulling before seeds set, removing much of the root system; effectively controlled using any of the several readily available general use herbicides such as glyphosate.

Credits: The information provided in this factsheet was gathered from efloras.org, Michigan Natural Features Inventory, Robert W. Freckmann Herbarium and the U.S. Forest Service.

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).


Common Name:

Japanese hop

Scientific Name:

Humulus japonicus

Family:

Cannabaceae
(Hemp)

Duration:

Annual, Perennial

Habit:

Vines

USDA Symbol:

HUJA