Rosa californica

Rosa californica, the California wildrose, or California rose, is a species of rose native to the U.S. states of California and Oregon and the northern part of Baja California, Mexico. The plant is native to chaparral and woodlands and the Sierra Nevada foothills, and can survive drought, though it grows most abundantly in moist soils near water sources. This thorny, flowering, fruit-bearing shrub is also deciduous, and grows vertically up to six feet tall. The meaning of its name is twofold; Rosa, that it resembles or is composed of roses, and californica, that it originates from California.

Description

A shrub. It grows 2 m high and spreads 1.8 m wide. The stems have stout prickles. The leaves are mid green. The flowers are pink and have a mild scent. They occur in clusters. They have 5 petals. The fruit are round hips that are orange-red. They are edible.

Edible Uses

The fruit can be eaten raw or cooked. When eaten raw after a frost it becomes soft and is much esteemed. It is rich in vitamins A and C. The fruit is about 15mm in diameter but has only a thin layer of flesh surrounding the many seeds — care should be taken when eating it (see known hazards). The seeds are a good source of vitamin E and can be ground and mixed with flour or added to foods as a supplement; be sure to remove the seed hairs first. The blossoms can be soaked in water to make a beverage.

Traditional Uses

The flowers are soaked in water to make a drink. The buds are eaten fresh. The fruit are used for food.

This uses section is brief — help expand it

Medicinal Uses

An infusion of the blossoms has been used as an analgesic and febrifuge to treat pain and fevers in infants. A decoction of the hips has been drunk to treat kidney complaints, indigestion, rheumatism, sore throats, fevers, and colds, and used externally as a wash on scabs and sores. An infusion of the seeds has been used for stomach fevers and painful congestion. The fruit is a very rich source of vitamins A, C, and E, flavonoids, and other bio-active compounds, and is also 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. It does best in a moist loamy soil and an open sunny position. It is resistant to frost but sensitive to drought. It suits hardiness zones 5-10. Hobart Botanical Gardens.

Where It Grows

Australia, Mexico, North America*, Tasmania, USA,

Cultivation

Succeeds in most soils, preferring a circumneutral soil and a sunny position. Grows well in heavy clay soils. Dislikes water-logged soils. The flowers have a rich perfume. 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. The plant that is most commonly grown under this name is in fact R. nutcana. 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 need a warm period following a cold one to mature the embryo and soften the seedcoat. To speed this up, scarify the seed and place it in damp peat at 27–32°c for 2–3 weeks until imbibed, then hold at 3°c for four months, by which time germination should begin. Alternatively, 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 as soon as ripe in a cold frame sometimes germinates in spring, but may take 18 months. Stored seed should be sown as early as possible and stratified for 6 weeks at 5°c; germination may still take 2 years. Prick seedlings into individual pots when large enough to handle. Plant out in summer if over 25cm tall; otherwise overwinter in a cold frame and plant out in late spring. Half-ripe cuttings with a heel taken in July in a shaded frame, overwintered and planted out in late spring, give a high success rate. Hardwood cuttings of pencil-thick shoots, 20–25cm long, taken in early autumn and planted in a sheltered spot outdoors or in a cold frame, take up to 12 months to establish but normally succeed at a high rate. Suckers can be divided and replanted directly in their permanent positions during the dormant season. Layering takes 12 months.

Other Uses

An essential oil obtained from the flowers and leaves is used in perfumery. The unsplit stems have been used as rims in twined basketry.

Notes

There are about 150 Rosa species and many cultivated varieties.

Synonyms

References (11)

• Beckstrom-Sternberg, Stephen M., and James A. Duke. "The Foodplant Database." http://probe.nalusda.gov:8300/cgi-bin/browse/foodplantdb.(ACEDB version 4.0 - data version July 1994)
• Bocek, B. R., 1984, Ethnobotany of Costanoan Indians, California, Based on Collections by John P. Harrington. Economic Botany 38(2): 240-255
• Bodkin, F., 1991, Encyclopedia Botanica. Cornstalk publishing, p 888
• Brickell, C. (Ed.), 1999, The Royal Horticultural Society A-Z Encyclopedia of Garden Plants. Convent Garden Books. p 892
• Cundall, P., (ed.), 2004, Gardening Australia: flora: the gardener's bible. ABC Books. p 1213

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