Herb: Japanese Rose
Latin name: Rosa multiflora
Family: Rosaceae (Rose Family)
Medicinal use of Japanese Rose:The leaves are poulticed and applied to sores. The fruit is anodyne, diuretic, hypoglycaemic and laxative. It is also antidotal to fish poisoning. It is used to treat constipation and articular pain and as an application to foul ulcers, wounds, sprains and injuries. The seed is laxative and diuretic. The root is rich in tannins. It is astringent and carminative. The fruit of many members of this genus is a very rich source of vitamins and minerals, especially in vitamins A, C and E, flavanoids and other bio-active compounds. It is also a fairly good source of essential fatty acids, which is fairly unusual for a fruit. It is being investigated as a food that is capable of reducing the incidence of cancer and also as a means of halting or reversing the growth of cancers.
Description of the plant:
Habitat of the herb:On slopes, in scrub, or by rivers at elevations around 1300 metres in China.
Edible parts of Japanese Rose:Fruit - raw or made into preserves, pies etc. The fruit is about 7mm in diameter, but there is only a thin layer of flesh surrounding the many seeds. The fruit is rich in carotene (81.4mg per 100g) and vitamin C. Some care has to be taken when eating this fruit, see the notes above on known hazards. Young leaves and shoots - raw or cooked. Used as they emerge from the ground in spring. The young leaves contain more than 200mg per 100g of vitamin C. The seed is a good source of vitamin E, it can be ground and mixed with flour or added to other foods as a supplement. Be sure to remove the seed hairs. The seed contains about 8% oil.
Other uses of the herb:The plant is fairly wind tolerant and can be grown as a shelter hedge though it can be damaged by salt laden winds. The plant has a dense sturdy habit and makes an excellent hedge. The root contains 23-25 per cent of tannin. An essential oil obtained from the fresh flowers is used in the cosmetic industry. The plant also has an extensive root system and is used for soil stabilization. This species can also be used as a rootstock for other species of rose, especially for ramblers and when grown on poor soils.
Propagation of Japanese Rose:Seed. Rose seed often takes two years to germinate. This is because it may need a warm spell of weather after a cold spell in order to mature the embryo and reduce the seedcoat. One possible way to reduce this time is to scarify the seed and then place it for 2 - 3 weeks in damp peat at a temperature of 27 - 32°C (by which time the seed should have imbibed). It is then kept at 3°C for the next 4 months by which time it should be starting to germinate. Alternatively, it is possible that seed harvested "green" (when it is fully developed but before it has dried on the plant) and sown immediately will germinate in the late winter. This method has not as yet(1988) been fully tested. Seed sown as soon as it is ripe in a cold frame sometimes germinates in spring though it may take 18 months. Stored seed can be sown as early in the year as possible and stratified for 6 weeks at 5°C. It may take 2 years to germinate. Prick out the seedlings into individual pots when they are large enough to handle. Plant out in the summer if the plants are more than 25cm tall, otherwise grow on in a cold frame for the winter and plant out in late spring. Cuttings of half-ripe wood with a heel, July in a shaded frame. Overwinter the plants in the frame and plant out in late spring. High percentage. Cuttings of mature wood of the current seasons growth. Select pencil thick shoots in early autumn that are about 20 - 25cm long and plant them in a sheltered position outdoors or in a cold frame. The cuttings can take 12 months to establish but a high percentage of them normally succeed. Division of suckers in the dormant season. Plant them out direct into their permanent positions. Layering. Takes 12 months.
Cultivation of the herb:On slopes, in scrub, or by rivers at elevations around 1300 metres in China.
Known hazards of Rosa multiflora:There is a layer of hairs around the seeds just beneath the flesh of the fruit. These hairs can cause irritation to the mouth and digestive tract if ingested.
Plant information taken from the Plants For A Future.