It is an invasive species in a number of countries.Lonicera japonica, the Japanese honeysuckle or suikazura (／吸- in Japanese; jinyinhua in Chinese; 忍 in Chinese and Japanese) is a species of honeysuckle native to eastern Asia including China, Japan and Korea. It is a twining bine able to climb up to 10 metres (33 ft) high or more in trees, with opposite, simple oval leaves 3-8 centimetres (1.2-3.1 in) long and 2-3 centimetres (0.79-1.18 in) broad. The flowers are double-tongued, opening white and fading to yellow, and sweetly vanilla scented. The fruit is a black spherical berry 3-4 millimetres (0.12-0.16 in) diameter containing a few seeds.
This species is often sold by American nurseries as the cultivar 'Hall's Prolific' (Lonicera japonica var. halliana). It is an effective groundcover, and has pleasant, strong-smelling flowers. It can be cultivated by seed, cuttings, or layering. In addition, it will spread itself via shoots if given enough space to grow.
In both its native and introduced range, Japanese honeysuckle can be a significant source of food for deer, rabbits, hummingbirds and other wildlife.
The variety L. japonica var. repens has gained the Royal Horticultural Society's Award of Garden Merit.
Japanese honeysuckle has become naturalized in Argentina, Australia, Brazil, Mexico, New Zealand and much of the US, including Hawaii, as well as a number of Pacific and Caribbean islands.
Japanese honeysuckle is classified as a noxious weed in Texas, Illinois, and Virginia, and is banned in New Hampshire. It grows extremely rapidly in parts of America such as southwestern Ohio and is virtually impossible to control in naturalized woodland edge zones due to its rapid spread via tiny fruit seeds. It forms a tall dense woody shrub layer that aggressively displaces native plants. It is also very difficult to manage in semi-wild areas, such as in large rural yards.
It is listed on the New Zealand National Pest Plant Accord as an unwanted organism.
It can be controlled to some degree via labor-intensive methods such as cutting or burning the plant to root level and repeating at two-week intervals until nutrient reserves in the roots are depleted. It can also be controlled through annual applications of glyphosate, or through grubbing if high labor and soil destruction are not of concern. Cutting the honeysuckle to within 5-10 cm of the ground and then applying glyphosate has proven to be more effective, provided that the mixture is rather concentrated (20-25%) and is applied immediately after making the cut.
Lonicera japonica contains methyl caffeate, 3,4-di-O-caffeoylquinic acid, methyl 3,4-di-O-caffeoylquinate, protocatechuic acid, methyl chlorogenic acid and luteolin. These compounds have an inhibitory effect on human platelet aggregation that may explain the possible role of Japanese honeysuckle in maintaining vascular homeostasis. The two biflavonoids, 3-O-methyl loniflavone and loniflavone along with luteolin and chrysin can be isolated from the leaves. Other phenolic compounds present in the plant are hyperoside, chlorogenic acid and caffeic acid.
The two secoiridoid glycosides, loniceracetalides A and B, can be isolated, together with 10 known iridoid glycosides, from the flower buds.
The plant also contains the saponins loniceroside A and B and the antiinflammatory loniceroside C.
In traditional Chinese medicine,Lonicera japonica is called rn dōng téng (Chinese: 忍; literally "winter enduring vine") or jīn yín huā (Chinese: --; literally "gold silver flower"). Alternative Chinese names include er hua and shuang hua. In Korean, it is called geumeunhwa. The dried leaves and flowers (Flos Lonicerae Japonicae) are employed in traditional Chinese medicine, being used to treat fever, headache, cough, thirst and sore throat.
In 2014, Chinese researchers led by Dr Chen-Yu Zhang of Nanjing University reported that "MIR2911, a honeysuckle (HS)-encoded atypical microRNA, directly targets IAVs with a broad spectrum."