Rosa roxburghii
Sweet Chestnut Rose
Taxonomy and growth
Uses
Toxicity
Toxicity warning. The historical record reports a hazard for this plant. Do not use it to decide which parts are safe to eat or use medicinally.
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.
Edible uses
Fruit - raw or cooked[3]. The fruits are aromatic and very spiny, they remain greenish even when ripe[8]. The fruit is very rich in vitamins and has a sweet sour taste[11]. The fruit is up to 4cm long[7], but there is only a thin layer of flesh surrounding the many seeds[K]. Some care has to be taken when eating this fruit, see the notes above on known hazards. The seed is a good source of vitamin E, it can be ground into a powder and mixed with flour or added to other foods as a supplement[1][5]. Be sure to remove the seed hairs[1].
- Plant part
- Fruit
- Plant part
- Seed
Medicinal uses
Historical medicinal uses. These records describe reported uses. They do not establish safety or effectiveness. Ask a qualified health professional before using any plant medicinally.
The plant is rich in tannins and is used as an astringent[9]. 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[8].
- Product or use
- Astringent
- Product or use
- Cancer
Environment
- Range
- E. Asia - China, Himalayas.
- Habitat
- Waysides and semi-arid river valleys[2]. On open slopes, in valleys, at roadsides, or in curbs at elevations of 500 - 2500 metres[11].
- Light
- full sun
- Shade tolerance
- light shade
- Water
- moderate
- Hardiness
- Zone 5+
- Soil textures
- sandy, loamy, clay, heavy clay
- Soil pH
- acid, neutral, alkaline
- Drainage
- well drained
- Tolerates Nutritionally Poor Soil
- No
- Drought
- intolerant
Propagation
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[13]. One possible way to shorten 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[13]. 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[13]. Seed sown as soon as it is ripe in a cold frame sometimes germinates in spring though it may take 18 months[K]. Stored seed should be sown as early in the year as possible and stratified for 6 weeks at 5°c[7]. It may take 2 years to germinate[7]. 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[12]. High percentage[12]. 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[12][7]. The cuttings can take 12 months to establish but a high percentage of them normally succeed[12]. Division of suckers in the dormant season. Plant them out direct into their permanent positions. Layering. Takes 12 months[2].
Cultivation
Succeeds in most soils[2], preferring a circumneutral soil and a sunny position[7]. Succeeds in poor sandy soils[8]. Grows well in heavy clay soils. Dislikes water-logged soils[7]. This species was first described from a double-flowered form, so the typical species (which is single-flowered) is called R. roxburghii normalis[8]. The flowers have a fruity perfume[10]. The mature fruits smell like ripe pineapples[10]. Grows well with alliums, parsley, mignonette and lupins[4][6]. Garlic planted nearby can help protect the plant from disease and insect predation[4][6]. Grows badly with boxwood[4]. Hybridizes freely with other members of this genus[13]. Plants in this genus are notably susceptible to honey fungus[7].
References
Kavasch. B. Native Harvests. Vintage Books 1979-00-00 ISBN 0-394-72811-4
Bean. W. Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement. Murray 1981-00-00
Kunkel. G. Plants for Human Consumption. Koeltz Scientific Books 1984-00-00 ISBN 3874292169
Philbrick H. and Gregg R. B. Companion Plants. Watkins 1979-00-00
Facciola. S. Cornucopia - A Source Book of Edible Plants. Kampong Publications 1990-00-00 ISBN 0-9628087-0-9
Riotte. L. Companion Planting for Successful Gardening. Garden Way, Vermont, USA. 1978-00-00 ISBN 0-88266-064-0
Huxley. A. The New RHS Dictionary of Gardening. 1992. MacMillan Press 1992-00-00 ISBN 0-333-47494-5
Matthews. V. The New Plantsman. Volume 1, 1994. Royal Horticultural Society 1994-00-00 ISBN 1352-4186
Duke. J. A. and Ayensu. E. S. Medicinal Plants of China Reference Publications, Inc. 1985-00-00 ISBN 0-917256-20-4
Genders. R. Scented Flora of the World. Robert Hale. London. 1994-00-00 ISBN 0-7090-5440-8
Flora of China 1994-00-00 http://flora.huh.harvard.edu/china/
Sheat. W. G. Propagation of Trees, Shrubs and Conifers. MacMillan and Co 1948-00-00
McMillan-Browse. P. Hardy Woody Plants from Seed. Grower Books 1985-00-00 ISBN 0-901361-21-6