Rosa obtusifolia

Desv.

Rosaceae Edible: Fruit, Seeds Potential hazards — see below 1,736 iNaturalist observations

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Summary

A deciduous shrub, hardy to UK zone 5. Flowers June to July. Bee-pollinated hermaphrodite. Adapts to light sandy, medium loamy, and heavy clay soils preferring drainage. Tolerates mildly acid, neutral, or mildly alkaline soils. Grows in semi-shade or full sun; prefers moist soil.

Description

Edible Uses

The fruit can be eaten raw or cooked and is rich in vitamin C. Only a thin layer of flesh surrounds the many seeds. Care should be taken when eating the fruit — see known hazards. The seeds are a good source of vitamin E and can be ground and mixed with flour or added to food as a supplement; always remove the seed hairs first.

Medicinal Uses

The fruit is a very rich source of vitamins and minerals, particularly vitamins A, C, and E, flavonoids, and other bio-active compounds, and is a fairly good source of essential fatty acids, which is unusual for a fruit. It is being investigated for its potential to reduce the incidence of cancer and to halt or reverse cancer growth.

Known Hazards

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.

Distribution

It is a temperate plant.

Where It Grows

Britain, Europe,

Cultivation

Succeeds in most soils, preferring a circumneutral soil and a sunny position. Grows well in heavy clay soils. Dislikes water-logged soils. Grows well with alliums, parsley, mignonette and lupins. Garlic planted nearby can help protect the plant from disease and insect predation. Grows badly with boxwood. Closely related to R. canina. Hybridizes freely with other members of this genus. Plants in this genus are notably susceptible to honey fungus.

Propagation

Rose seed often takes two years to germinate, as it may require a warm period following a cold spell to mature the embryo and reduce the seedcoat. One approach to shorten this is to scarify the seed and place it in damp peat at 27–32°c for 2–3 weeks until it has imbibed, then keep it at 3°c for four months until germination begins. Seed harvested green — fully developed but not yet dried on the plant — and sown immediately may germinate in late winter, though this method had not been fully tested as of 1988. Seed sown fresh in a cold frame sometimes germinates in spring but may take 18 months. Stored seed should be sown as early in the year as possible and stratified for 6 weeks at 5°c; it may still take 2 years to germinate. Prick out seedlings into individual pots when large enough to handle. Plant out in summer if plants exceed 25cm, otherwise overwinter in a cold frame and plant out in late spring. Half-ripe heel cuttings taken in July in a shaded frame, overwintered and planted out in late spring, give a high success rate. Mature cuttings of pencil-thick current-season shoots, 20–25cm long, taken in early autumn and planted in a sheltered spot or cold frame, can take 12 months to establish but normally succeed at a high rate. Suckers can be divided in the dormant season and planted directly into permanent positions. Layering takes 12 months.