China Rose
Rosa chinensis Jacq.
Synonyms -
Family: - Rosaceae.
Names:
Rosa is Latin for rose.
Chinensis refers to its country of origin.
China Rose is the English translation of the scientific name.
Other Names:
Summary:
An erect, deciduous shrub, 1-2 m tall with smooth and hairless stems and varying levels of flat, curved thorns to thornless. It has red, white, pink or purple flowers with 5 or more petals that produce smooth red hips. Normally it has 3-5 leaflets that are shiny on top and duller green underneath.
Description:
See the Weedy Blackberry and Rose key.
Cotyledons:
Two.
First leaves:
Leaves:
Alternate, deciduous, 50-110 mm long including the petiole. 3-5 rarely 7 leaflets. Main axis sparsely prickly and glandular hairy.
Stipules - Mostly joined to the petiole, the free parts are ear-like. Surface often glandular hairy. Tip pointed. Edges smooth
Petiole - Yes. Sparsely prickly.
Blade - Of leaflet, egg shaped to oblong, 25-60 mm long by 10-30 mm wide, prickles on the veins. Length to width ratio of 2 to 2.5. Dark green and often shiny on top, green underneath, almost smooth and hairless on both sides. Edges acute toothed (serrate). Pointed tip. Base broadly tapering to almost rounded.
Stems:
Erect, round in cross section, almost smooth and hairless. Branchlets purple to brown. The thorns are abundant to absent, curved, flat and stout.
Flower head:
Usually 4-5 flowers in a flat plane and rarely single at the ends of the stems. Flower stalk (pedicel) 25-60 mm long, almost smooth and hairless to glandular hairy. 1-3 bracts that are parallel sided, smooth and hairless with glandular or smooth edges and a pointed tip.
Flowers:
Red, pink, white or purple, slightly fragrant, 40-50 mm diameter.
Ovary -
Style - Free, exserted, hairy, nearly equalling the stamens.
Sepals - 5 at the top of the floral tube, deciduous (caducous), egg shaped, sometimes leaf like, densely hairy on top and smooth and hairless underneath. Edges usually with a few pinnate lobes and rarely smooth. Tip pointed and tail like.
Petals - 5, semi double or double, red, pink, white or purple, egg shaped, base broadly tapering, tip with a broad shallow notch. Petals attached to the edge of the floral tube.
Stamens - Many of varying lengths. Usually yellow. Attached to the edge of the floral tube.
Anthers -
Fruit:
Red, egg shaped, to pear shaped, 10 20 mm diameter, smooth and hairless hip.
Seeds:
Many, small.
Roots:
Taproot and many laterals.
Key Characters:
Shrub.
Leaves compound, stipulate, leaflets 3-5.
Stipules adnate to petioles, persistent, glandular-pubescent at margin.
Flowers 4 or 5, rarely solitary, slightly fragrant or not.
Petals various shades of white, pink, purple or red.
Sepals often pinnately lobed.
Styles free, exserted, slightly shorter than stamens.
Hip ovoid or pyriform.
Hypanthium globose to urceolate, rarely depressed-globose.
Achenes inserted at walls and flat base of hypanthium.
Adapted from Flora of China.
Biology:
Life cycle:
Perennial.
Physiology:
Reproduction:
Flowering times:
Seed Biology and Germination:
Vegetative Propagules:
Hybrids:
Three varieties recognised:
Rosa chinensis var. chinensis. has double or semi double flowers, branches robust, often with hooked prickles; leaflets 3-5, rarely 7, abaxially dark green; flowers several, rarely solitary; petals red, pink, or white.
Rosa chinensis var. semperflorens (Curtis) Koehne has double or semi double flowers, branches slender, with short prickles; leaflets 5-7, thinner, often tinged with purple-red; flowers often solitary, or 2 or 3 and fasciculate; petals deep red or deep purple.
Rosa chinensis var. spontanea has 5 petalled flowers
Allelopathy:
Population Dynamics and Dispersal:
Origin and History:
China.
Distribution:
QLD, SA, VIC.
Habitats:
Climate:
Temperate.
Soil:
Plant Associations:
Significance:
Beneficial:
Ornamental and widely cultivated.
Detrimental:
Minor environmental weed.
Toxicity:
Not recorded as toxic.
Symptoms:
Treatment:
Legislation:
None.
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 competitive, preferably perennial, pastures 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 garden 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®), 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 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 sprays 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 Blackberry). 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:
Pests include Aphids, Heliothis, 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)
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:
Bodkin, F. (1986). Encyclopaedia Botanica. (Angus and Robertson, Australia).
Lazarides, M. and Cowley, K. and Hohnen, P. (1997). CSIRO handbook of Australian Weeds. (CSIRO, Melbourne). #863.3.
Randall, J.M. and Marinelli, J. (1996) Invasive Plants. (Brooklyn Botanic Gardens Inc. Brooklyn). P. Photo.
http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200011233 Flora of China.
Acknowledgments:
Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.