Common Name:

General Information

Gleditsia japonica is a deciduous tree usually growing 18 - 21 metres tall. The trunk and branches are very formidably armed with branched, slightly flattened spines[].
The tree is harvested from the wild for local use as a food, medicine and source of materials. It issometimes cultivated for its various uses, especially in agroforestry systems in China, Japan and Korea, and is grown as a hedge[].

Known Hazards

None known

Botanical References

, ,

Range

E. Asia - China, Japan, Korea.

Habitat

Damp sandy soils[]. Sunny slopes, valleys, streamsides, near roads and in forests at elevations of 100 - 2500 metres in northeast China[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	20.00 m
Growth Rate	Medium
Pollinators	Insects
Cultivation Status	Cultivated, Wild

Cultivation Details

Gleditsia japonica is fairly cold-hardy, with older trees being able to tolerate temperatures down to around -20°c when fully dormant. The tree has a habit though, especially when young, of producing new growth until quite late in the season. Especially in areas where the summers are not hot, this new growth will not ripen fully and will be liable to be cut back by the cold in the winter. Older plants tend to lose this habit. Generally, the plant should be considered to only be hardy to about -5°c when young, especially if growing in areas with cooler summers[].
Easily grown in a loamy soil, requiring a sunny position[]. Succeeds in most soils[]. Tolerates drought once established[] and atmospheric pollution[].
Trees at Kew in London (hardiness zone 7) produced lots of pods and fertile seeds in the hot summer of 1989, they also fruited well in the cool summer of 1993 and also in 1994, 95 and 96[].
Trees are cultivated for their seedpods in Japan[].
Trees have a light canopy, they come into leaf late in the spring and drop their leaves in early autumn[] making them an excellent canopy tree for a woodland garden.
Plants in this genus are notably resistant to honey fungus[].
This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[].

Edible Uses

Seed - cooked. The seed is roasted, dehusked, soaked until soft then boiled and eaten with sugar[]. The seed contains 22.4% protein and 2.8% fat[].
The scimitar-shaped seedpods are 20 - 25cm long and 25 - 30mm wide[]. The seed is up to 10mm long and 7mm wide[].

Young leaves - cooked[, ]. A famine food used when all else fails[].

Medicinal

Gleditsia sinensis and closely related species are widely used in traditional Chinese medicine. All parts of the plant are used, but perhaps the most important are the spines found on the trunk and branches[].
The spines are said to be antiinflammatory, antimicrobial, antipruritic, antitumor, cardioprotective and expectorant, and have also shown anti-HIV activity[176. 279, ]. They are used in the treatment of cancer, acute purulent inflammation, dermatopathies and tonsillitis[, ]. They are used in the treatment of coughs, constipation and liver diseases[].
Dried and powdered, the spines are used in the treatment of swellings, especially on the breasts. Either as a powder or in decoction, they are used as a mouthwash for treating abscesses and as a wash for treating ulcers and skin diseases in general[, ].
The spines should not be used by pregnant women since they have a stimulant effect upon the uterus and could induce a miscarriage[, ].

The fruits and seeds are important as a mucus-loosening and diuretic drug[].

The leaves are astringent, A decoction is used to bathe wounds[].

The root and bark are ingested as an anthelmintic and an antifebrile[].

The pods are said to be bechic, depurative, emetic and purgative[]. They are used in the treatment of flatulence, chronic dysentery, intestinal and urinary obstructions, and prolapse of the rectum[].

The fruit and the spines contain a number of medically active constituents including saponins and flavonoids[].

Agroforestry Uses:

When planted close together and severely pruned, most Gleditsia species form good windbreaks and hedges. With their usually very spiny trunks and branches, the hedge becomes an effective barrier, and with its ability to fix atmospheric nitrogen, it also enriches the soil[, ].

Other Uses

The pulp contained in the seedpods is rich in saponins and can be used as a soap[, , , , ]. It is used as a washing agent and for cleaning furniture[]. It is obtained from the seed according to another report[].

An extract of the seedpods is used as an ingredient in commercial cosmetic preparations as a skin conditioner[].

The fruits are a source of tannins[].

The wood is strong, durable, coarse-grained[]. The heartwood has a beautiful pink colour[]. The wood can be used for props, carpentry work and building[].

Propagation

Seed - pre-soak for 24 hours in warm water and then sow in spring in a greenhouse[]. The seed should have swollen up, in which case it can be sown, if it has not swollen then soak it for another 24 hours in warm water. If this does not work then file away some of the seed coat but be careful not to damage the embryo[]. Further soaking should then cause the seed to swell. One it has swollen, the seed should germinate within 2 - 4 weeks at 20°c. As soon as they are large enough to handle, prick the seedlings out into individual deep pots and plant them out into their permanent positions in the summer. Give the plants some protection from the cold for their first few winters outdoors.