Bladder Dock

Acetosa vesicaria

Synonyms - Rumex vesicarius, Rumex roseus

Family: POLYGONACEAE

Names:

Other Names:

Ruby dock, red dock, pink dock, rosy dock.
Summary:     
Ruby dock is an erect, stout fleshy annual herb up to 1 m high. The leaves are broadly triangular, 5-10 cm long with rounded basal lobes. The stem leaves are somewhat smaller. The inflorescences are large and spike-like with inconspicuous pinkish flowers enclosed by showy valves which enlarge in fruit. The fruiting valves are pink to purple or red, inflated, circular in shape, 12-20 mm long and finely lined.
It is native to northern Africa and from the Middle East to India and a common weed of disturbed areas and fairly arid areas. It flowers in spring.
Very closely related to Rumex species, it differs in its enlarged leaf bases and in its fewer (2 or 3) flowers at each whorl of the inflorescence.

Description:

Cotyledons:

Two.

First leaves:

Leaves:

Glaucous, thick, ovate and somewhat lobed at the base (cordate)
Stipules - Yes
Petiole - 50-100 mm long.
Blade - 50-100 mm long.
Stem leaves -

Stems:

Stout, hollow, fleshy, striate, fleshy, branched, erect. 200-1000 mm tall.
Flower stem - 200-1000 mm tall.

Flower head:

Spike like. Single flowers drooping in racemes which form panicles 120-130 mm long

Flowers:

Mainly solitary
Pedicels - 7-8 mm long and jointed (articulate) above the middle.
Ovary -
Perianth - Pink, 16-22 mm long x 13-18 mm wide deeply notched at each end of the valves resembling wings about 7 mm wide, membranous, reticulate.
It has no tubercle and no marginal nerve around the edge of the wing.
Stamens -
Anthers -

Fruit:

Pink, membranous.

Seeds:

Polygonal.

Roots:

Stout taproot

Key Characters:

Annual
Perianth segments or lobes 6, pink, conspicuous, unequal, 3 outer segments small, 3 inner ones large.

Biology:

Life cycle:

Annual. Grows with winter rains.

Physiology:

Reproduction:

By seed

Flowering times:

Spring.
July to September in WA.

Seed Biology and Germination:

Ruby Dock seeds are polymorphic (light and dark of various shades) and of high potential viability. Seeds are enclosed within showy, papery fruiting valves at maturation. Extracted seeds are characterised by non-deep physiological dormancy. Light and dark seeds usually require an after-ripening period of several months, but thereafter germinate at any time of the year in a light-dark rhythm. Light seeds also show excellent germination in constant darkness; they are non-dormant. Dark seeds show conditional dormancy, where germination is inhibited in darkness, but not in a light-dark rhythm. Scarification experiments indicate that the conditional dormancy of dark seeds is related to the pericarp. The pericarp may restrict oxygen consumption by the embryo, contain chemical inhibitors and/or impede radicle protrusion. A range of environmental variables is likely to affect the specific germination requirements of particular seed types. Environmental conditions may induce secondary dormancy, in both light and dark seeds 1.

Vegetative Propagules:

Hybrids:

Allelopathy:

Population Dynamics and Dispersal:

Spread by fruit floating in water, adhering to animals or machines and in produce.

Origin and History:

Native to northern Africa and south west Asia.

Distribution:

ACT, NSW, NT, QLD, SA, VIC, WA.


Courtesy Australia's Virtual Herbarium.

Habitats:

Climate:

Arid areas.

Soil:

Sandy alluvial soils and gravelly ironstone soils.

Plant Associations:

Significance:

Beneficial:

Palatable stock feed in dry areas.
Ornamental

Detrimental:

Weed of disturbed areas and roadsides
Competes with native plants.

Toxicity:

Contains oxalate.
Not recorded as toxic.
A related species R. crispus contains rumicin.

Symptoms:

Treatment:

Legislation:

Management and Control:

Prevent seed set.

Thresholds:

Eradication strategies:

In bushland, individual plants may be wiped with a mixture of 1 L glyphosate(450g/L) in 2 L water. Small infestations may be sprayed with 0.5g chlorsulfuron(600g/kg) plus 100 mL Tordon® 75-D in 10 L of water in winter. This mix controls existing plants and has residual activity to control seedlings for about a year.
Blanket wiping with 1 L glyphosate(450g/L) plus 20 g chlorsulfuron(750g/kg) plus 2 L water in spring is reasonably selective in pastures. This mix may be applied manually to individual plants.
2 L/ha glyphosate(450g/L) can be used selectively in some seasons when dock is green in autumn or summer and the annuals are not. Metsulfuron is also effective.
Some seed will remain viable in the soil for 20 years.
Grazing, mowing and cultivation usually lead to greater stands.
Plant tall growing perennial species to increase the levels of shade and help reduce re-invasion.

Herbicide resistance:

Biological Control:

Related plants:

Rumex roseus is very similar but has the lateral nerves ending in a continuous nerve which forms the edge of the wing and the pedicels are jointed (articulate) below the middle. It is now considered to be the same species as Acetosa vesicaria.
Acetosa sagittata (Rambling Dock) has scrambling stems and doesn't have the distinctive pink fruits.

Related Rumex species:
Bladder Dock (Rumex vesicarius now Acetosa vesicaria)
Broadleaf Dock (Rumex obtusifolius)
Clustered Dock (Rumex conglomeratus)
Curled Dock (Rumex crispus) is a tall plant up to 1.5 m high with pointed oval leaves that are 4-24 cm long. The leafless inflorescence has densely clustered flowers and fruits. The fruit valves are reddish brown, swollen in the centre, with smooth margins and lacking teeth.
Fiddle Dock (Rumex pulcher) is a plant to 50 cm tall with rounded oblong leaves, the basal ones sometimes slightly constricted in the middle and appearing fiddle-shaped. The leaves are 4-15 cm long. The leafy inflorescence has distant whorls of flowers and fruits. The fruit valves are brown, swollen and warty in the centre and the margin has prominent stiff teeth.
Mud Dock (Rumex bidens)
Rambling Dock (Rumex sagittatus now Acetosa sagittata)
Shiny Dock (Rumex crystallinus)
Sorrel (Rumex acetosella now Acetosella vulgaris)
Wiry Dock (Rumex dumosus)

Plants of similar appearance:

Doublegee (Emex australis) looks similar before flowering.

References:

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P282. Diagram.

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

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

Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney).

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

Hussey, B.M.J., Keighery, G.J., Cousens, R.D., Dodd, J. and Lloyd, S.G. (2007). Western Weeds. A guide to the weeds of Western Australia. (Second Edition). Plant Protection Society of Western Australia, Perth, Western Australia. P. Photo.

Lazarides, M. and Cowley, K. and Hohnen, P. (1997). CSIRO handbook of Australian Weeds. (CSIRO, Melbourne). #10.2, P5.

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). P

McBarron, E.J. (1983). Poisonous plants. (Inkata Press, Melbourne). P61.

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). P459

Randall, J.M. and Marinelli, J. (1996) Invasive Plants. (Brooklyn Botanic Gardens Inc. Brooklyn). P. Photo.

Acknowledgments:

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