Japanese Hops (Humulus japonicus)
Key Identification Features
Description
Japanese Hops is an annual climbing vine, reaching up to 35 feet in a growing season, that can have negative impacts on the resiliency of native plants in the area they infest. The leaves are usually 5 lobed, but they can have up to 9, and the ones closer to the top often have 3. These leaves are opposite along the stem and are 2-5 inches long. There are prickles along the stem that orient downwards. The flowers are green and have 5 petals. The female and male plants are separate, or dioecious, so the females have downward facing clusters of flowers while the males have upright flowers on stems. The fruit is ovoid in shape and appears yellow-brown.
Native Range
Japanese Hops originates in temperate regions of Asia. It was brought into North America as an ornamental, but also for use as an Asian tonic.
Habitat and Dispersion
This invasive vine prefers fertile and moist soil. It thrives in floodplain habitats where it can spread over the entire area. Japanese Hops is often found along the edges of streams and lakes and within wet meadows. The seeds are dispersed via wind and water.
Best Management Practices
To manage small infestations of Japanese Hops, hand-pulling may be an effective method. This must be done prior to seed maturation to avoid new plants from becoming established next season. The pulled plants must also be removed from the area to avoid any re-rooting of leaf nodes.