Macartney Rose
Rosa bracteata Wendl.
Synonyms - Rosa macartnea, Rosa sinica var. braamiana
Family: - Rosaceae
Names:
Rosa is Latin for rose.
Bracteata refers to the prominent bracts below the flowers.
Other Names:
Noisette Rose
Summary:
A thorny, evergreen, diffuse rose with hairy arching stems to 3 m tall. It has white to yellowish 5 petalled flowers and leaves with 5-7 leaflets. The hip is hairy but has no prickles.
Description:
See the Weedy Blackberry and Rose key.
Cotyledons:
Two.
First leaves:
Leaves:
Alternate, 5-9 leaflets, 40-90 mm long including the petiole.
Stipules - Usually free but may be joined to the petiole at the base. Edges are comb like. Densely hairy and glandular.
Petiole - Yes. Sparsely hairy and with short prickles.
Blade - Of leaflet, egg shaped to elliptic, 10-35 mm long by 5-20 mm wide, leathery, finely toothed and the teeth tend to be rounded (crenate). Length to width ratio is 1.6-2. Tip flat topped, to rounded to slightly pointed. Base broadly tapering to rounded. Hairless and shiny on the top side and hairless or with a few hairs especially on the midvein on the underside.
Stems:
Erect to arching, 0.5-3 m long, round in cross section with strong, straight to curved thorns. The thorns are often in pairs below the leaves and up to 9 mm long. Flat smaller thorns and glandular bristles are often present and dense to scattered further down the stems. Densely hairy. The branchlets are purple brown.
Flower head:
1-3 at the ends of the stems. Closely subtended by several, large, egg shaped bracts with comb like or irregularly incised edges. The bracts are densely hairy on the underside almost smooth and hairless on top. Flower stalk (pedicel) less than10 mm long, densely hairy, sparsely glandular
Flowers:
White to yellowish, 45-90 mm diameter.
Ovary -
Styles - free, densely hairy, slightly exerted, slightly shorter than the stamens.
Sepals - 5, at the top of the floral tube, egg shaped, densely hairy on the underside and sparsely hairy on top. Tip pointed to tail like. Edges smooth. Persistent and bent back when in fruit.
Petals - 5, attached to the edge of the floral tube, egg shaped, base broadly tapering, tip with a broad shallow notch.
Stamens - Many of varying lengths. Usually yellow. Attached to the edge of the floral tube.
Anthers -
Fruit:
Globose hip, 13-30 mm diameter, densely hairy with no prickles. Sepals are bent back and remain attached to the hip.
Seeds:
Many, small.
Roots:
Taproot and many laterals.
Key Characters:
Branches densely hairy.
Flowers with prominent bracts.
Sepals entire.
Hypanthium densely hairy with no prickles.
Hip densely hairy with no prickles.
Adapted from Harden.
Biology:
Life cycle:
Perennial. Evergreen.
Physiology:
Reproduction:
Flowering times:
Seed Biology and Germination:
Vegetative Propagules:
Hybrids:
Two varieties are recognised.
Rosa bracteata var. bracteata has branchlets that are densely tawny pubescent, intermixed with scattered bristles and glandular bristles.
Rosa bracteata var. scabriacaulis has branchlets that are densely bristly and glandular bristly.
Allelopathy:
Population Dynamics and Dispersal:
Origin and History:
Native to China.
Distribution:
NSW, QLD, SA, VIC.
Habitats:
Creek lines, seashores, roadsides
Climate:
Temperate.
Soil:
Sandy hills.
Plant Associations:
Scrub, mixed forests.
Significance:
Beneficial:
Ornamental.
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:
Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P217. Photo.
Bodkin, F. (1986). Encyclopaedia Botanica. (Angus and Robertson, Australia).
Harden, Gwen J. (1991). Flora of NSW. (Royal Botanic Gardens, Sydney). Volume 1. P541. Diagram.
Lazarides, M. and Cowley, K. and Hohnen, P. (1997). CSIRO handbook of Australian Weeds. (CSIRO, Melbourne). #863.1.
Randall, J.M. and Marinelli, J. (1996) Invasive Plants. (Brooklyn Botanic Gardens Inc. Brooklyn). P. Photo.
www.efloras.org - Flora of China.
Acknowledgments:
Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.