Rubus roribaccus (L.H.Bailey) Rydb.

Rubus roribaccus is a member of the Raspberry group of Rubus species and is native to the USA.
Synonyms - Rubus canadensis var. roribaccus, Rubus flagellaris var. michiganensis, var. occidualis, Rubus flagellaris var. roribaccus , Rubus imperiorum, Rubus michiganensis, Rubus occidualis, Rubus pauperrimus, Rubus procumbens var. roribaccus, Rubus villosus var. michiganensis, Rubus villosus var. roribaccus.

Family: Rosaceae.


Rubus is from the Latin ruber meaning red and refers to the red immature berries.
Roribaccus refers to.
Dewberry refers to

Other names:


Dewberry is a sprawling, thorny, semi-deciduous, perennial shrub with bluntly angled canes and 3-5 leaflet leaves The white flowers have 5 petals and are single or a cluster of up to 8 flowers at the ends of short branches. The fruits are large, black and elongated.


See the Weedy Blackberry and Rose key.



First leaves:


Alternate. 3-5 leaflets, if the latter then arranged pedately. The basal leaflet pair is sometimes lobed.
Stipules -
Petiole - (30)50-80 mm long. Lateral petiolule 2-10 mm long. Terminal petiolule 20-40 mm long.
Blade - of leaflets. Terminal leaflet (30)40-60(100) mm long, (30)60-80 mm wide, broadly elliptic. Tip shortly pointed (acuminate). Edges double toothed (biserrate). Base rounded to obliquely and broadly wedge shaped (cuneate). Upper and lower surface a similar colour. Lower surface green, with a few pilose hairs that are mostly on the veins and the lamina is visible.


Primocanes trailing, slender and stolon-like, bluntly angled, the angles channelled on dry specimens. Sparse non glandular pilose hairs mixed with many sessile, dark glandular hairs or hairless. Initially primocanes may have a white bloom but it disappears with age. Prickles 2-3 mm long, straight or curved, patent or declined and not confined to the angles with 5-10 per 5 cm length. Primocanes take root where the touch the ground near their ends.

Flower head:

1-5(8) flowers in a cluster (subcorymbose raceme) at the ends of a series of short, 50-150 mm lateral shoots from the leaf axils of the primocane. The first-formed flowers are usually solitary in the axils of a 3-leaflet leaf, Basal floral leaves have a petiole 10-30 mm long, lateral petiolules 0-1 mm long, terminal petiolule 3-8 mm long. The terminal leaflet is 25-60 mm long x 15-35 mm wide. Axis (rachis) covered with non- glandular pilose hairs.


White with 5 petals and on stalks (pedicels) 20-40 mm long.
Ovary - Young carpels glabrous.
Sepals - densely non-glandular pubescent hairy, not armed, bent back (reflexed), tip pointed (apex apiculate).
Petals - 5, white, 16-20 mm long, 10-15 mm wide, elliptic to obovate, touching or not, not crumpled, not cupped, tip rounded
Stamens - Many.
Anthers - without pilose hairs,


Oblong to 40 mm long, ripening purple to black, not separating from receptacle, not hollow. Black when mature.



Key Characters:

Primocanes trailing or prostrate, slender and stolon like, obscurely angled, channelled when dry.
Primocanes sparingly non-glandular pubescent or glabrous, but with many sessile dark red glands.
Prickles 2-3 mm long.
Upper and lower leaf surfaces not differing markedly in colour.
Floral rachis densely pubescent with erect non-glandular hairs.
Floricanes short stems from successive leaf axils, terminating in a 1-8-flowered raceme.
Pedicels 20-60 mm long.
Flowers with 5 white petals, functionally bisexual.
Fruit large and black when mature.
Adapted from Robyn and Bill Barker and USDA.


Life cycle:



Tolerates full sun to full shade but plants grow slowly in full shade.


By seed and tip rooting or layering.

Flowering times:

Seed Biology and Germination:

Seed short lived in the soil.

Vegetative Propagules:

Hybrids and Varieties:

Lucretia Dewberry


Population Dynamics and Dispersal:

Dumping of garden refuse and intentional plantings are the main methods of dispersal.
Seedling survival is usually low.

Origin and History:

Native to USA.


Courtesy Australia's Virtual Herbarium.


Water courses and damp areas.


Temperate, humid and sub-humid regions with an annual rainfall greater than 500 mm.


Plant Associations:



Berries are picked for food, preserves, jam, pies, wine, liqueurs.
Fruit is rich in vitamin C.
Widely cultivated since 1876.


Minor weed of disturbed areas. Sparingly naturalised.


Not recorded as toxic.


Management and Control:

Grazing provides control.
Seedlings rarely establish in dense pasture.
Control with herbicides is usually the most cost effective. Metsulfuron and triclopyr plus picloram are expected to be effective. Glyphosate can be used in home gardens or other sensitive areas.
Basal bark applications using Access® plus diesel can be used where canes are removed mechanically.
In Pine plantations hexazinone can be used.
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 Dewberry bush (or 2.5 square metres of low lying bushes). This is equivalent to about 4000 L/ha of spray mix being applied.
In large infestations, consider using the cheaper metsulfuron for a year or two to reduce the size of the infestation then follow up with the more effective and costly triclopyr + picloram herbicides.


Eradication strategies:

3 annual, summer applications of 1 L of Grazon® plus 250 mL of Pulse® Penetrant in 100 L of water is expected to provide eradication on most sites. Replant native 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 plant is actively growing, provides a cheaper option to reduce the size of the infestation before Grazon® is used.

Herbicide resistance:

None reported.

Biological Control:

Biological control agents introduced for European Blackberry control have little effect on Dewberry.

Related plants:

There are no native Rubus species in WA.
Blackberry (Rubus anglocandicans = Rubus discolor = Rubus procerus, Rubus fruticosus, Rubus ulmifolius)
Blackberry (Rubus anglocandicans) is the main weedy variety in WA. Its main flowering is in December to January and it has white flowers (though it may be pinkish in the bud). The leaves tend to be whitish on the lower surface.
Boysenberry is a cross between a Raspberry (Rubus idaeus), a Blackberry (Rubus fruticosus), an American Dewberry (Rubus aboriginum) and a Loganberry (Rubus × loganobaccus). It has narrow straight thorns.
California Dewberry (Rubus ursinus) is not naturalised in Australia.
Cutleaf Blackberry (Rubus laciniatus ssp. laciniatus) has cut leaf - see diagram.
Dewberry (Rubus roribaccus) is in NSW and Victoria.
Elmleaf Blackberry (Rubus ulmifolius) has pinkish petals and smaller leaves than R. anglocandicans. Some varieties are thornless.
Keriberry (Rubus rugosus) has leaves that are green on top and whitish underneath and roundish canes covered in brown hairs.
Kittatinny Blackberry (Rubus bellobatus)
Loganberry (Rubus loganobaccus, Rubus x loganobaccus) has narrow straight thorns and usually flowers later than blackberry.
Mountain Raspberry (Rubus gunnianus)
Native Raspberry (Rubus hillii = Rubus moluccanus var. trilobus A.R.Bean) is a native of the east coast of Australia and has simple palmately lobed leaves
that tend to be green on the upper an lower surfaces. The flowers are white with no pink tinges there are glandular hairs on the canes that look like red dots under a hand lens.
Plains or Bundy (American) Blackberry (Rubus laudatus) flowers in September to November with fruit in December - somewhat earlier than Raspberry (Rubus idaeus)
Rose-leaved Bramble (Rubus rosifolius) is a native plant of the east coast of Australia.
Thimbleberry (Rubus parvifolius, Rubus rosifolius) is a native plant of the east coast of Australia and Tasmania. It has almost stalkless leaflets with the upper side being green and the underside almost white. The flowers are pink to red flowers on 2-3 cm stalks.
Wineberry (Rubus phoenicolasius)
Yellow Raspberry (Rubus ellipticus)
Rubus alceifolius
Rubus chloocladus
Rubus cissburiensis
Rubus discolor = Rubus procerus is not in Australia but the older literature refers to R. anglocandicans as R. discolor in Western Australia and R. procerus in the eastern states.
Rubus koehleri
Rubus leightonii
Rubus odoratus is similar to Thimbleberry and occurs in SA and Tasmania.
Rubus polyanthemus
Rubus pyramidalis
Rubus radula
Rubus rosaceus
Rubus selmeri = R. laciniatus
Rubus vestitus

Apple (Pirus malus), Pear (Pirus communis), Quince (Cydonia vulgaris), Loquat (Eriobotrya japonica), Plum (Prunus domestica), Apricot (Prunus armeniaca), Almond (Prunus amygdalus), Peach (Prunus persica) and Strawberry (Fragaria vesca) are all in the same family as Raspberry.

Plants of similar appearance:

See the Weedy Blackberry and Rose key.
Climbing Roses.


Barker, Robyn and Barker, Bill (2005). Blackberry. An identification tool to introduced and native Rubus in Australia. Edition 1.00. State Herbarium of South Australia.

Harden, Gwen J. (1991). Flora of NSW. (Royal Botanic Gardens, Sydney). Volume 1. P533. Diagram.


Collated by HerbiGuide. Phone 08 98444064 or for more information.