Japanese hop

Urticales > Cannabaceae > Humulus japonicus Siebold & Zucc.
Japanese hop is an annual, climbing or trailing vine that is native to eastern Asia. This vine has 5-lobed leaves (generally), downward pointing prickles on the stem and bracts at the base of the petioles. Leaves are opposite, rough, 2-5 in. (5-13 cm) long, 5-9 lobed with toothed margins. Most leaves will have 5 lobes, but the upper leaves may only have 3. Flowers originate in the leaf axils and are green with 5 petals. Male and female flowers occur on separate plants (dioecious). Female flowers occur in cone-shaped clusters that hang down and the male flowers occur in upright flower stems. Fruit is an achene. Japanese hop was introduced into North America in the mid-to-late 1800s as an ornamental. These vines can grow to 35 ft. (10.7 m) in one growing season.

Identification, Biology, Control and Management Resources

  • Weed of the Week - USDA Forest Service
    http://www.na.fs.fed.us/fhp/invasive_plants/weeds/japanese-hop.pdf - Nov 7, 2006

Selected Images

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Number:1334130
Description: Foliage; Martin County, KY
Photographer:Chris Evans, River to River CWMA
 Additional Resolutions and Image Usage
 
Number:1334131
Description: Foliage; Martin County, KY
Photographer:Chris Evans, River to River CWMA
 Additional Resolutions and Image Usage
 
Number:1334132
Description: Feature(s); The down-curved bracts and sharp prickles help to identify this plant
Photographer:Chris Evans, River to River CWMA
 Additional Resolutions and Image Usage
 
Number:5272027
Description: Fruit(s);
Photographer:Leslie J. Mehrhoff, University of Connecticut
 Additional Resolutions and Image Usage
 
Number:5272026
Description: Foliage; Leaves and Inflorescences
Photographer:Leslie J. Mehrhoff, University of Connecticut
 Additional Resolutions and Image Usage
 
Number:1334129
Description: Infestation; Martin County, KY
Photographer:Chris Evans, River to River CWMA
 Additional Resolutions and Image Usage
 
Number:5272028
Description: Plant(s);
Photographer:Leslie J. Mehrhoff, University of Connecticut
 Additional Resolutions and Image Usage
 
Number:5272030
Description: Infestation;
Photographer:Leslie J. Mehrhoff, University of Connecticut
 Additional Resolutions and Image Usage
 
Number:5307058
Description: Seed(s);
Photographer:Carole Ritchie, USDA NRCS PLANTS Database
 Additional Resolutions and Image Usage
 

External Links

Invasive Reference(s)

Subject Reference(s)

  • USDA, NRCS. 2001. The PLANTS Database, Version 3.1, National Plant Data Center, Baton Rouge, LA 70874-4490 USA. - http://plants.usda.gov/