Sweet Briar

Rosa rubiginosa L.

Synonyms - Rosa aglanteria, Rosa eglanteria.

Family: Rosaceae.

Names:

Rosa is Latin for rose.
Rubiginosa is from the Latin rubiginosa meaning rusty red and probably refers to the orange red fruit or the reddish hairs on the calyx and leaves.
Sweet Briar because the leaves when crushed and flowers have a sweet fragrance. Briar is from the Old English brer or braert and is a name for thorny shrubs.

Other names:

Briar Rose.
Eglantine (UK)
Mosqueta Rose
Sweet Brier (NZ)
Sweet Brier Rose (USA).

Summary:

A domed or erect, scrambling, woody, deciduous shrub or hedge plant, 1-4 metres tall with prickly stems and leaves. The aromatic leaves are composed of 5-9 toothed leaflets. Suckering occurs freely from the crown and bushes often exceed 1 metre in diameter at the base. It has pink or white pleasantly aromatic flowers with 5 overlapping petals from October to December on a spiny flower stalk.

Description:

See the Weedy Blackberry and Rose key.

Cotyledons:

Two.

Leaves:

Alternate, light green. Compound, pinnate, with 5-9, short stalked, leaflets. Sweet apple-like fragrance when rubbed. Fall off in winter (deciduous).
Stipules - Leafy and attached to the petiole and clasping the stem.
Petiole - Spiny with many, curved thorns and glandular hairs.
Blade - Of leaflets, oval to egg shaped, 8-40 mm long x 5-20 mm wide, edges serrated or multi toothed. Almost hairless on top, hairy underneath with soft and glandular hairs. Glandular hairs on the teeth and edges. Terminal leaflet is larger than the side leaflets and its tip is more pointed. Spiny on the midrib. Tip rounded. Edges toothed.

Stems:

Many, erect or arching, arising from the base, 1000-3000 mm tall, smooth and to red when young, becoming woody and rough with age. Short branches, which tends to curve upward, are carried towards the top of the stem. Many, backward directed, curved, stout thorns, to 18 mm long. Stems may have glandular hairs.
Upper fruiting branches have short bristles.

Flower head:

Loose clusters of 1-3 flowers in a corymb on short side shoots, with prickles and glandular hairs, at the ends of stems. Flower stalks (peduncles) glandular bristly.

Flowers:

Sweet scented, 25-45 mm in diameter, on stalks (pedicels), 10-15 mm long with prickles or stiff glandular hairs. Elongated sepals are a feature of the flower.
Ovary - Short hairy styles up to 2 mm above orifice of the disk. Ovule pendulous. Receptacle ('hip') red, swollen, egg shaped, 15-20 mm long.
Sepals - 5, erect, green, overlapping, lance shaped, 3 outer sepals with deep, slender lobes, up to 15 mm long when in flower and enlarging when in fruit. Stiff glandular hairs that are sometimes reddish on the back and along the edges, downy hairs on the inside. Persistent but free from the fruit.
Petals - 5, overlapping, pink to white petals, 8-22 mm long, longer than sepals.
Stamens - Many. Filaments 1.5-8 mm long.
Anthers - 1-1.5 mm long.

Fruit:

Enlarged flower base (torus or 'hip'), egg shaped to oblong to almost spherical, 10-25 mm long, orange to red to almost black. Hairless to glandular hairy and sometimes prickly near the base. Sepals often persist. Sheds in autumn after leaf fall. Several to many seeds in each hip.

Seeds:

Many, hairy, superior, 1 seeded, yellow, irregular shaped, angled seeds (carpels) that are bony when ripe. Carpels, 2-7 mm long, enclosed within but free from the fleshy, berry-like hollow red torus or 'hip'.

Roots:

Shallow perennial rootstock with many, long laterals in the top 300 mm of soil.

Key Characters:

Woody, prickly shrubs.
Leaflets glandular beneath.
Stipules adnate to petiole.
Calyx single
Petals, 5.
Distinct floral tube which develops into a hollow succulent torus or receptacle
Carpels becoming achenes free within the torus.
Adapted from J.M. Black, N.T. Burbidge and E.M. Bennett.

Biology:

Life cycle:

Perennial. The plant reproduces from seed. Germination occurs at any time of year with a peak in autumn and spring. The young plants are relatively tender and can be grazed off by sheep (or rabbits). Seedlings grow very slowly and most young seedlings die in the first summer. An area bared by disturbance is usually required to get seedling recruitment. Plants do not normally flower until they are two or three years old. Flowering starts in late spring and continues into summer. The hips ripen in late summer to autumn period and are held on the bushes into winter after the leaves have fallen. Some canes die each winter during its dormant period. New leaves and growth appear in spring. It suckers freely from the crown and individual plants may reach a considerable size with several hundred canes. Suckering is enhanced when slashing, burning, cultivation or some herbicides damage the plant. Once established it may survive for over a hundred years in Australia.

Physiology:

Tolerates frost.

Reproduction:

By seed, suckers, root and crown fragments and perennial rootstocks.
Insect pollinated but capable of self pollination and cross pollination.

Flowering times:

Spring and summer in western NSW.
October to December in SA.
November to January in Victoria.
November to December in Perth with fruit from December to March.
November to January in New Zealand.

Seed Biology and Germination:

Seed germinates at any time of year with a flush in early spring.
Seed requires cold stratification of 50 C or less for 2-6 weeks.
Seed remains viable in the soil for 3-4 years.

Vegetative Propagules:

Perennial rootstocks.

Hybrids:

It forms hybrids with Dog Rose (Rosa canina).

Allelopathy:

Population Dynamics and Dispersal:

Originally spread by intentional plantings but this is rare now.
Spread is mainly by seed via birds, foxes and animals that eat the fruit and pass the seeds. Some seed or fruit is also spread by water flows.
Dumped garden waste and contaminated soil can also be a significant source of new infestations.
Produces large amounts of seed but few seedlings survive. Grazing with sheep (or rabbits) often kills seedlings.
It is occasionally sold in nurseries or locally traded. European migrants commonly collect fruit for jams, beverages and herbal medicine.
In New Zealand it rapidly spread after control of rabbits.

Origin and History:

Europe. Western Asia. Northern India.
Probably in NSW by 1803.
Naturalised in Tasmania before 1838, SA by 1839 and Victoria by 1850. In Victoria it had covered 'large areas' by 1917.
Listed as the second most important weed of NSW in 1895.

Distribution:

ACT, NSW, QLD, SA, TAS, VIC, WA.
Present in all parts of Tasmania. Locally heavy infestations of up to 1 ha or more are found in parts of the Midlands and the North.
Argentina, New Zealand, South Africa, USA

Courtesy Australia's Virtual Herbarium.

Habitats:

More abundant in open situations with little competition.
Grasslands, tussock grasslands, grassy woodlands, dry and wet sclerophyll forests, river beds, riparian areas, rocky outcrops.

Climate:

Temperate. Mediterranean. Humid and sub humid cool temperate areas.
Usually in areas with an annual rainfall of more than 600 mm.
Tolerates frost and seasonally hot dry periods once established.

Soil:

Grows on a wide range of soil types.
More abundant on well drained, calcareous soils of moderate to high fertility.
Rarely on sands or poorly drained areas.

Plant Associations:

Significance:

Beneficial:

Ornamental and hedge plant.
Young leaves and shoots eaten by stock but mature plants are protected by their prickly nature.
Honey plant producing much pollen.
The hips have a high vitamin C content and are sometimes collected and processed for human consumption and to make a syrup. They contain 10-20 times more vitamin C than oranges or lemons.
Fruits can be eaten and young shoots candied. It has also been used in wines, sauces and jellies.
Used in herbal medicine for liver ailments, worms, baldness and snakebite.

Detrimental:

Weed of roadsides, range lands, streams, channel banks, pastures, old homesteads, plantations and disturbed areas.
Harbours vermin such as rabbits and restricts stock movements especially near watering points.
Contaminates hay with prickly stems.
Seldom a problem in improved pasture but occasionally competes with species suitable for grazing.
It may be a host for fruit fly.
It forms thickets that prevent most other species establishing.
Invades disturbed bushland.

Toxicity:

Not recorded as toxic.
Broken hips rubbed onto the skin cause an unpleasant itching.

Legislation:

Noxious weed of ACT, NSW, SA, TAS, VIC.
Secondary Weed of Tasmania.

Management and Control:

In bushland situations, plant or encourage species that reduce light levels.
Slashing and deep ploughing or ripping in winter to bring the roots to the surface and summer cultivation to expose them to the sun usually gives good levels of control in agricultural situations. Replant to vigorous pasture species to prevent seedling establishing.
It is often difficult to control manually due to the production of suckers, coppicing and layering. All material needs to be burnt on site.
Grazing with goats can provide control.
Slashing alone is generally ineffective.
Mechanical removal, or slashing and burning followed by cultivation, can provide control if repeated regularly and then followed by planting of a competitive, preferably perennial, pasture species that are grazed by cattle or goats.
Seedlings rarely establish in dense pasture or undisturbed native vegetation.
Control with herbicides is usually the most cost effective. Metsulfuron and triclopyr plus picloram have provided the best results. Glyphosate can be used in home gardens or other sensitive areas. Dead canes may be burnt or slashed in the following season to allow access and rehabilitation of the site.
Fire provides little control alone but assists access for herbicide application or other controls.
Triclopyr (Garlon®) or triclopyr + picloram (Grazon®) generally provides good control any time the plant is actively growing with good leaf area.
Basal bark spraying the lower 50 cm of the stems with triclopyr or Access® in diesel at flowering to early fruiting provides good control.
In Pine plantations hexazinone can be used.
Hexazinone as a spot treatment on the soil is also effective.
Imazapyr as an overall spray when the plant is in full leaf to fruiting provides good control also and has a soil residual to help control suckers.
Follow up treatments are essential for high levels of control and to control suckering at the periphery of the bush in the season following spraying.
Low volume spraying is usually effective providing the amount of active ingredient applied per bush is kept constant.
For high volume spraying use 1 litre of mix for each 2.5 cubic metres of Rose bush (or 2.5 square metres of low lying bush). This is equivalent to about 4000 L/ha of spray mix being applied.

Thresholds:

Eradication strategies:

Mechanical control is difficult and most of the root system must be removed for effective control.
3 annual, summer applications of 1 L of Grazon® plus 250 mL of Pulse® Penetrant in 100 L of water will eradicate most infestations. Replant native or agricultural species after control has been achieved.
On large infestations, 10 g metsulfuron(600g/kg) plus 250 mL Pulse® Penetrant in 100 L water, applied in summer when the Rose is actively growing, provides a cheaper option to reduce the size of the infestation before Grazon® is used.
In urban and sensitive areas repeated applications of 1 L glposate450 in 100 L water will eventually provide high levels of control.

Herbicide resistance:

None reported.

Biological Control:

Bio control agents are under evaluation.
Pests include Aphids, Helicoverpa, Spider Mite and Thrips.
Diseases include Black Spot, Botrytis Blight, Dieback, Mosaic Virus and Powdery Mildew.

Related plants:

Cherokee Rose (Rosa laevigata) has white flowers and bristly fruit.
Chestnut Rose (Rosa roxburghii) has pink to red-purple flowers and a hip covered with fine prickles.
China Rose (Rosa chinensis)
Dog Rose (Rosa canina) is scrambling with pink and white flowers, 5 leaflet leaves and was a rootstock of ornamental roses.
French Rose (Rosa gallica)
Japanese Rose (Rosa multiflora) is invasive in the USA.
Macartney Rose (Rosa bracteata) has white, 5 petal flowers.
Manetti or Noisette Rose (Rosa chinensis x moschata) has pink many petal flowers and 3-5 leaflet leaves.
Musk Rose (Rosa moschata)
Sweet Briar (Rosa rubiginosa) has pink, 5 petal flowers and 5-7 leaflet leaves.
Rambler Rose (Rosa chinensis x multiflora) has pink to red flowers, the pedicels don't have prickles and it has 5-7 leaflets leaves.
Tea Rose (Rosa odorata)

Plants of similar appearance:

See the Weedy Blackberry and Rose key.
Blackberry (Rubus species) usually have palmate rather than pinnate leaves and a berry-like fruit rather than a “rose hip”.

References:

Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P216-217. Photos.

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P397.

Blood, K. (2001). Environmental weeds: a field guide for SE Australia. (CH Jerram & Associates, Australia). P78-79. Photos.

Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P192-193. Diagram.

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P345. Photo.

Harden, Gwen J. (1991). Flora of NSW. (Royal Botanic Gardens, Sydney). Volume 1. P541. Diagram.

Hussey, B.M.J., Keighery, G.J., Cousens, R.D., Dodd, J. and Lloyd, S.G. (1997). Western Weeds. A guide to the weeds of Western Australia. (Plant Protection Society of Western Australia, Perth, Western Australia). P209.

Hyde-Wyatt, B.H. and Morris, D.I. (1980) The Noxious and Secondary Weeds of Tasmania. (Tasmanian Department of Agriculture, Hobart, Tasmania). P54-55. Diagram.

Lamp, C. and Collet, F. (1990). A Field Guide to Weeds in Australia. (Inkata Press, Melbourne). P269. Photo.

Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). #1066.4.

Marchant, N.G., Wheeler, J.R., Rye, B.L., Bennett, E.M., Lander, N.S. and Macfarlane, T.D. (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P209.

Muyt, A. (2001). Bush Invaders of South-East Australia: a guide to the identification and control of environmental weeds found in South East Australia. (R.G and F.J. Richardson, Australia). P217. Photos.

Paczkowska, G. and Chapman, A. (2000). The Western Australia flora: a descriptive catalogue. (Wildflower Society of Western Australia (Inc), the Western Australian Herbarium, CALM and the Botanic Gardens & Parks Authority). P512.

Parsons, W.T. and Cuthbertson, E.G. (1992). Noxious weeds of Australia. (Inkata Press, Melbourne). P572-575. Photos.

Roy, B., Popay, I., Champion, P., James, T. and Rahman, A. (1998). An Illustrated Guide to Common Weeds of New Zealand. (New Zealand Plant Protection Society). P266. Photo.

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.