Japanese Honeysuckle

Lonicera japonica

Physical Characteristics

Lonicera japonica is an evergreen Climber growing to 5 m (16ft) by 5 m (16ft) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 4. It is in leaf all year, in flower from June to July. The species is hermaphrodite (has both male and female organs) and is pollinated by Moths. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers dry or moist soil.

Distribution

E. Asia - China, Japan, Korea. Locally naturalized in Britain[50].

Habitats

Woodland Garden Dappled Shade; Shady Edge; Ground Cover;

Edible Uses

Edible Parts: Flowers Leaves Edible Uses: Tea Leaves - cooked. The parboiled leaves are used as a vegetable[183]. Some caution is advised, see notes above on toxicity. Flowers - sucked for their sweet nectar[183], used as a vegetable or made into a syrup and puddings[183]. A tea is made from the leaves, buds and flowers[177, 183].

Medicinal Uses

Antibacterial Antiinflammatory Antispasmodic Antiviral Depurative Diuretic Dysentery Febrifuge Skin TB VD The stems and flower buds are alterative, antibacterial, anti-inflammatory, antispasmodic, depurative, diuretic, febrifuge[147, 174, 176, 178, 238]. The plant is also used to reduce blood pressure[174, 176, 238]. The stems are used internally in the treatment of acute rheumatoid arthritis, mumps and hepatitis[238]. The stems are harvested in the autumn and winter, and are dried for later use[238]. The stems and flowers are used together as an infusion in the treatment of upper respiratory tract infections (including pneumonia) and dysentery[238]. An infusion of the flower buds is used in the treatment of a wide range of ailments including syphilitic skin diseases and tumours, bacterial dysentery, colds, enteritis, pain, swellings etc[174, 176, 218, 222, 238, 279]. Experimentally, the flower extracts have been shown to lower blood cholesterol levels and are antibacterial, antiviral and tuberculostatic[222, 279]. Externally, the flowers are applied as a wash to skin inflammations, infectious rashes and sores[238]. The flowers are harvested in early morning before they open and are dried for later use[238]. The plant has a similar action to Forsythia suspensa and is usually used in combination with that species to achieve a stronger action[176]. This plant has become a serious weed in many areas of N. America, it might have the potential to be utilized for proven medical purposes[222].

Known Hazards

The leaves contain saponins[179]. Saponins are quite toxic but are poorly absorbed by the human body and so most pass through without harm. They can be found in many common foods such as some beans. Thorough cooking, and perhaps changing the cooking water once, will normally remove most of the saponins. Saponins are much more toxic to some creatures, such as fish, and hunting tribes have traditionally put large quantities of them in streams, lakes etc in order to stupefy or kill the fish[K].