Biosecurity Spotters logo

Bladder campion (Silene vulgaris)

Bladder Campion can form dense patches that compete with crops and pasture, and its seeds can contaminate harvested pasture seed. It also competes with native plants in coastal areas and can persist in gardens and other neglected places.

Key facts

Type: Weed, herb.

Native to: Western Europe, through Scandinavia and eastwards through Siberia to Japan.

Established in: NSW, VIC, TAS, SA, WA.

Other names: Blue Root, Rattlebox.

Identification

  • A long-lived, hairless to sparsely hairy herb that dies back to a substantial woody rootstock after flowering and fruiting.
  • Its thin, upright or slightly arched stems can reach 90 cm long and have opposite pairs of smooth, grey-green leaves.
  • Flowers have five white, rarely pinkish, deeply notched petals and a distinctive inflated, egg-shaped calyx with 20 to 30 visible veins.
  • The capsule remains enclosed in the inflated calyx and releases numerous dark grey, kidney-shaped seeds through six small teeth.
  • Look-alike: Silene dioica and S. latifolia have a similar general growth habit, but lack Bladder Campion's inflated calyx and are softly hairy rather than hairless to sparsely hairy.

Where it grows

In Australia it occurs in cultivated ground, waste places and coastal areas, including parts of eastern Australia, South Australia, south-western Western Australia and eastern Tasmania.

Why it matters

  • Dense patches compete with crops and can limit their growth.
  • Seeds shed at about the same time as those of some pasture species can contaminate harvested seed, and the plant can reduce pasture production.
  • On sandy coasts it competes with native herbaceous plants and has been reported as invasive in dry coastal vegetation.
  • It can persist in neglected or abandoned gardens and spread under or over fence lines.

How it spreads

  • Wind shakes seeds from the capsules, dispersing them locally; on exposed coastal dunes and foreshores, some seeds travel with wind-blown sand.
  • Seeds can be carried in mud or soil on animals, footwear and vehicles.
  • Root fragments can be moved to new areas on earthmoving machinery during cultivation or grading.

Control options

  • Use a targeted control program because this deep-rooted perennial is not controlled by routine maintenance of perennial pastures.
  • Chemical control may require repeated applications of appropriate registered herbicides; the plant is resistant to several commonly used herbicides.
  • Split herbicide applications may be needed because uneven clumps can shield late-emerging shoots.
  • Grub out small infestations and follow up for young plants emerging from the soil seed bank.

Hygiene and washdown

  • Remove soil and seeds from footwear and vehicles before leaving an infested site, as seeds can travel in adhering mud or soil.
  • Clean earthmoving and cultivation machinery to avoid carrying soil or root fragments to new areas.
  • Inspect and clean vehicles, plant and footwear before leaving an infested area, paying attention to tyres, radiators, belly plates, tracks and floor mats.
  • Wash down at a designated bay where runoff is contained and can be monitored for seedlings.
  • Record each washdown so the client has evidence of clean entry and exit.

Classification by state

  • Australia (national): No national listing. Managed under state and territory law.
  • Queensland: Not prohibited or restricted. Not listed as prohibited or restricted matter in Queensland. Everyone must also take all reasonable and practical steps to minimise its risks (the general biosecurity obligation).
  • New South Wales: Not a priority weed. Not a state or regional priority weed in NSW. The general biosecurity duty applies: anyone dealing with it must prevent, eliminate or minimise the risk it poses.
  • Victoria: Not declared. Not declared under the Catchment and Land Protection Act 1994. Other Victorian laws may still apply.
  • South Australia: Declared plant. Depending on the declaration, it can be an offence to move it on public roads or sell it, and landowners may be required to control it on their land.
  • Western Australia: Permitted, not declared. Listed as a permitted organism in WA, so it can be brought in, but it is not a declared pest.
  • Tasmania: Not declared. Not a declared weed in Tasmania. Other laws may still apply.
  • Northern Territory: Not declared. Not on the NT A to Z weed list, and Weeds Australia does not list it as declared in the NT. Check the NT declared weeds list before moving or planting it.
  • Australian Capital Territory: Not declared. Not declared under the Biosecurity Act 2023 (ACT). A general biosecurity duty still applies.

Legal obligations

Every state and territory places a duty on landholders and people working on land to prevent the spread of invasive species, such as the general biosecurity obligation in Queensland and the general biosecurity duty in New South Wales. Declarations and control requirements differ between states and local government areas, so check the current official list before work starts.

  • New South Wales: Biosecurity Act 2015 (NSW), administered by NSW Department of Primary Industries and Regional Development
  • Victoria: Catchment and Land Protection Act 1994 (Vic), administered by Agriculture Victoria
  • Tasmania: Biosecurity Act 2019 (Tas), administered by Biosecurity Tasmania
  • South Australia: Landscape South Australia Act 2019 (SA), administered by the regional landscape board
  • Western Australia: Biosecurity and Agriculture Management Act 2007 (WA), administered by the WA Department of Primary Industries and Regional Development

Sources