Quick Facts

Quick facts

• Broadleaf Dock (Rumex obtusifolius) is a tap-rooted perennial with more or less upright branches.
• It has persistent valves around its fruit and these have 2-5 teeth on the margins of each valve.
• It is an aggressive coloniser.
• It can hybridise with Curled Dock (Rumex crispus).
• It is an agricultural and environmental weed best controlled through an integrated management program.

What Does It Look Like?

What is it?

Broadleaf Dock (Rumex obtusifolius) is a tap-rooted perennial herb, 60–120 cm high, with spreading (to about 45 degrees) to more or less upright branches from about halfway up its main stem. It has a basal rosette of leaves. These leaves have a stalk usually longer than the blade. The blade is narrowly egg-shaped (ovate) to more or less oblong or elliptic, to 25 (rarely to 35) cm long, to about 12 cm wide, flat, with its tip blunt to pointed and its base round-lobed. Stem leaves are shorter stalked (Lousley & Kent 1981; Wilson 1990; Wilson, submitted).

The numerous flowers are in distinct, dense clusters spread along the branches. Flowers are on slender jointed stalks as long as or slightly longer than the flower, and have 6 greenish to white perianth segments (commonly called 'valves' in the docks).

The fruiting heads become rusty-brown and conspicuous. Each fruit (a 3–sided nut) is surrounded by 3 persistent, enlarged valves that are 3.5–6 mm long, with 2–5 teeth on their side margins and with a lump in the middle of the back of one valve (rarely on all 3 valves) (Lousley & Kent 1981; Wilson 1990; Wilson, submitted).

Broadleaf Dock is a polymorphic species (seed from the same population or the same plant differ in their requirements for germination) (Wilson 1990).

For further information and assistance with identification of Broadleaf Dock contact the herbarium in your state or territory.

Flower colour

Green

Growth form (weed type/habit)

Herb

Where it currently grows? Preferred habitat

Broadleaf Dock occurs from the coast to mountains and inland areas, and has a wide climatic range, from cool temperate to warm temperate regions but generally in moister cooler districts than Curled Dock. It occurs in a wide range of environments: cultivation, pasture, horticultural areas, roadsides, recreation areas and gardens. It is able to establish in seasonally damp situations in grasslands, woodlands, riverbanks, and low-lying areas (Parsons & Cuthbertson 2001; Page & Lacey 2006).

Are there similar species?

Broadleaf Dock (Rumex obtusifolius) differs from native species that have toothed valves in having relatively broad basal leaves (2-3 times as long as wide compared to 4-20 times as long as wide in the native species) and more or less upright branches that are straight and not curling. It differs from Fiddle Dock (Rumex pulcher) in having its flower clusters closer together (especially towards the tip of a branch) and lacking an obvious leafy bract. Its flowers are on slender stalks that become at least twice as long as the valves as they mature (in Fiddle Dock, the stalks are thickened and only about as long as the valves) (Wilson 1990, Wilson submitted).

Curled Dock (Rumex crispus) hybridises with Broadleaf Dock; the resulting plants have been called x Rumex pratensis Mertens & Koch and they look intermediate in features (Wilson 1990, Wilson submitted).

Illustrations showing the differences between the fruiting valves of dock species (with Rumex acetosella treated as Acetosella vulgaris in the later publications) are provided by Burbidge & Gray (1979), Lousley & Kent (1981), Stanley & Ross (1983), Chorney (1986), Wilson (1990), Auld & Medd (1992), Walsh (1996), Hussey et al. (1997) and Richardson et al. (2006).

Why Is It A Weed?

What are its impacts?

Agriculture: Broadleaf Dock is an agricultural and environmental weed that competes with pasture, crop and native species for space, light, moisture and nutrients. It can become the dominant herbaceous plant, particularly in irrigated production areas. Dense infestations can reduce grazing capacity and cause yield losses in pasture, infest irrigated orchards and other plantation crops and obstruct irrigation and drainage channels.

Broadleaf Dock has a large crown and dense leaf growth that is unpalatable. It crowds out more desirable species, and its large rootstock depletes available nutrients and moisture. It is a prolific seeder, generating about 60 000 seeds per plant (Page & Lacey 2006). It is an aggressive coloniser, with its root system to 2 m deep depleting soil nutrients and moisture (Parsons & Cuthbertson 2001). It contains oxalates and is suspected of poisoning stock although generally levels are unlikely to be high enough to kill stock (Everist 1973).

Native ecosystems: Infestations can also affect biodiversity by replacing native species in natural grassland, woodland, riverbank and other plant communities (for example, see Forestry Tasmania (1999), DPIW (2007), Kodela & Wilson 2007, pers. comm.).

How does it spread?

Broadleaf Dock disperses by seed. The mature fruits are attached to the dried branches by slender jointed stalks and are easily broken off (from mid-summer to winter) when the branches are brushed against by humans, animals or equipment. The toothed valves around the fruit are well equipped for dispersal by wind, water, animals and humans (Parsons & Cuthbertson 2001; Wilson 2007, pers. comm.).

The crown and upper taproot can regenerate from fragments created by cultivation equipment (Parsons & Cuthbertson 2001, Page & Lacey 2006).

What is its history in Australia?

It is not known exactly when or how Broadleaf Dock arrived in Australia. Early herbarium specimens date back more than a century. It probably came accidentally, possibly as a contaminant of seed or fodder, or in mud attached to equipment (Wilson 2007, pers. comm.).

How To Manage It?

Best practice management

Non-chemical control: Single plants of Broadleaf Dock can be controlled by deep hoeing or grubbing. For larger infestations, a combination of cultivation and herbicides is effective. Slashing and mowing are not effective. In pastures, infestation can be reduced by the spray/graze technique (Parsons & Cuthbertson 2001).

Biological control: Broadleaf Dock has also been recognised as a target for biological control through a cross-jurisdictional government process. This allows activities to be undertaken to develop effective biological controls. The docks biocontrol program which ran from 1982 to 1998 targeted Swamp Dock (R. brownii), Curled Dock (R. crispus), Broadleaf Dock (R. obtusifolius) and Fiddle Dock (R. pulcher). The program resulted in the release of one agent, the Clearwing Moth Pyropteron doryliformis. That has become widely established and provides almost total control in Western Australia and good control in approximately 50% of infested areas in Victoria and New South Wales (Page & Lacey 2006).

Chemical control: For up-to-date information on which herbicides are registered to control Broadleaf Dock and the best application methods and dosages, contact your state or territory weed management agency or local council.

Please also see the Australian Pesticides and Veterinary Medicines Authority for chemical information http://www.apvma.gov.au

For further information on management and control of Broadleaf Dock see Forestry Tasmania (1999) and the Tasmanian Department of Primary Industries and Water (2007).

Does it have a biological control agent?

YES

When does it grow? (lifecycle/growth calendar)

Established plants of Broadleaf Dock usually start growing from the rootstock in winter, and flower and fruit by early summer, when the above-ground branches die and turn brown (Parsons & Cuthbertson 2001).

Seed is usually polymorphic (seed from the same population or the same plant differ in their requirements for germination), with major germination periods in both autumn and spring. Many seeds of this species can remain dormant for a long time. Young plants overwinter as a rosette; aerial growth is slow until the taproot has developed. Densely crowded plants may not flower until the second year (Parsons & Cuthbertson 2001).

Where Is It Found?

Which states and territories is it found?

ACT, NSW, SA, TAS, VIC, WA

What areas within states and territories is it found?

Broadleaf Dock is naturalised sporadically near Perth, Manjimup and Albany in south-western Western Australia; and in south-eastern Australia, south from Tenterfield in northern New South Wales to Hobart in Tasmania and west to the Eyre Peninsula in South Australia (Wilson, submitted; Wilson 2007, pers. comm.).

Where does it originate?

There are about 200 species in the genus Rumex and nearly all parts of the world have native species. In Australia there are 7 native species and about as many again introduced. Broadleaf Dock is native to Europe and South-west Asia, but is widely introduced elsewhere and is considered one of the most important perennial weeds in the world (Zaller 2004).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?

NO

Where is it a declared weed?

Not declared in any Australian state or territory.

Government weed strategies and lists – Weeds Australia

Is it on the National Alert List for Environmental Weeds?

NO

Government weed strategies and lists – Weeds Australia

Is it on the Agricultural Sleeper List?

NO

Government weed strategies and lists – Weeds Australia

Names And Taxonomy

Main scientific name

Rumex obtusifolius

Other scientific names (synonyms)?

Does it have other known common name(s)?

Broad-leaved Dock, Bitter Dock