Leaf:  Opposite, simple, ovate to oval, entire margin, sometimes lobed, semi-evergreen, light green, somewhat pubescent.

Flower:  Fragrant, 1/2 to 1inch long, white or yellowish-white long petals, appearing in the May to early June in pairs.

Fruit:  Small (1/4 inch diameter), black berry, ripening in fall and persisting into early winter. 

Twig:  Slender, initially pubescent, light brown in color developing scaly thin bark, hollow pith. 

Bark:  Long, shreddy peeling strips, light red-brown to straw-colored. 

Form:  A scrambling, twisting vine with no tendrils or aerial roots, forms dense thickets in bushes and trees and sprawls along the ground. 

Discussion

Japanese honeysuckle climbs and drapes over native vegetation, shading it out.  It is capable of completely covering herbaceous and understory plants and climbing trees to the canopy.  The semi-evergreen condition of this honeysuckle allows for growth both prior to and after dormancy of other deciduous plants.  The prolific growth covers and smothers vegetation present, including understory shrubs and trees in forested communities.  Although this prolonged growth period is beneficial to the plant, it is also beneficial in controlling the plant.  Vegetative runners are most prolific in the open sun and will resprout where touching the soil, forming mats of new plants.  This honeysuckle will display little growth under moderate shade.  In deep shade, runners develop but often die back.  Flowering and seed development are heaviest in open-sun areas.  Seedling establishment and growth is slow in the first 2 years of development of a new honeysuckle colony.

Japanese honeysuckle was a native of Japan.  It was introduced to the U.S. in 1806 for horticultural uses and presently occurs as far north as Illinois.  It spreads rapidly into many open natural communities in the southern 2/3 of Illinois.  It has not been found to be a serious pest north of Peoria, although it is recorded from 10 northern Illinois counties.  Bitter cold winter temperatures appear to limit this species somewhat.  Nonetheless, this vine is becoming increasingly common in central Illinois.

This aggressive vine seriously alters or destroys the understory and herbaceous layers of the communities it invades, including prairies, barrens, glades, flatwoods, savannas, floodplain and upland forests. Japanese honeysuckle also may alter understory bird populations in forest communities.

Distinguishing  Characteristics

Japanese honeysuckle can be distinguished by the distinct white flowering buds, the stem with short bristly hairs, and the waxy coating on the leaves.   Japanese honeysuckle is distinguished easily from the native honeysuckle vines by its leaves.   Leaves near tips of the vines of Japanese honeysuckle are opposite and not united, while leaves of native honeysuckles (3 species) are united at the base, forming a single leaf surrounding the stem.

Distribution

Self-sustaining populations have established in southern New England and the Ohio Valley south to the Atlantic and Gulf coastal plains and west to the Mississippi Valley and Ozark Mountains of Missouri and Arkansas.

Japanese honeysuckle is widely planted across much of North America and frequently escapes cultivation. However, it is not usually invasive in areas outside the region described above. It can be found from Maine to Florida and from Michigan and Wisconsin south to Nebraska, Kansas, Oklahoma, and Texas. It is not reported from New Hampshire. It  is reported in southern Ontario, Hawaii, and Puerto Rico, and as an occasional escapee in the southwestern United States.

 Images

Click each small picture to see a larger image.

October, 2002 JA	October, 2002 JA	October, 2002 JA
October, 2002 JA	October, 2002 JA

Location

N 39.2777^°     W -89.88000^°                                                           
20 meters south of the west entrance to the fitness trail, Loveless Park, S. Locust Street, Carlinville, Macoupin County, IL.

Copyright 

Photos © 2002 Jon Anderson, Carlinville High School, linke@carlinvilleschools.net 

References

Virginia Polytechnic Institute and State University, College of Natural Resources.
http://www.fw.vt.edu/dendro/dendrology/syllabus/ljaponica.htm

Vegetation Management Guideline, Illinois Natural History Survey
http://www.inhs.uiuc.edu/edu/VMG/jhnysckl.html

William A. Nieting and Nancy C. Olmstead, Field Guide To North American Wildflowers:  Eastern Region, 1979, Alfred A. Knopf.

U.S. Department of Agriculture, Fire Effects Information System
http://www.fs.fed.us/database/feis/plants/vine/lonjap/distribution_and_occurrence.html

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