photo: Cleveland Metroparks
Japanese Hop (humulus japonica)
 Cleveland Metroparks |
 Cleveland Metroparks |
 Leslie J. Mehrhoff, University of Connecticut, Bugwood.org |
 Chris Evans, Illinois Wildlife Action Plan, Bugwood.org |
Form:
Acts as an annual or a perennial depending on climate. Grows up to 35' long with downward- pointing, rough, prickly hairs on stems and leaves. Stems are light green to reddish in color and twist counterclockwise around objects.
Leaves:
Opposite, palmately lobed in 5 or more parts, 2-5" long. Leaf stalks (petioles) are as long as or longer than the leaves. Spines at the base of each petiole point toward the soil surface.
Flowers:
Midsummer to early fall. Male and female flowers are found on separate plants (dioecious) where the leaf attaches to the stem (leaf axil). Male flowers are dull green and borne on stalks that grow upward. Female flowers are pale green and grow in downward-drooping clusters.
Fruits & Seeds:
Small (0.12" wide), dry, scale-like seeds that are easily dispersed by wind or water.
Roots:
Shallow fibrous roots.
Similar Species:
Common hop (Humulus lupulus) native
Bar cucumber (Sicyos angulatus) native
Tier 3 - Presence is of Interest
The species that occur in this tier are likely ornamental escapes. It is not known whether they are established and/or spreading within Cleveland Metroparks. The ecological impact is poorly known for these species.
Action: The presence of these plants should be recorded by approximating the number of plants. Initial population numbers are likely small.
