Common cotula

Cotula australis

Introduction: Cotula australis, commonly known as Australian cotula or brass buttons, is a perennial herbaceous plant belonging to the Asteraceae family. Native to Australia and New Zealand, it has also naturalized in various other regions. Recognized for its distinctive appearance and adaptability, this plant is often found in a range of habitats, from wetlands to disturbed areas.

Identification: 1. Morphology:

  • Height: Australian cotula typically grows close to the ground, with a height ranging from 10 to 30 centimeters.
  • Leaves: The fern-like leaves are finely divided and feathery, giving the plant a delicate appearance.
  • Stems: Prostrate or ascending stems that root at nodes, forming dense mats.

2. Flowers:

  • Inflorescence: The small, button-like flower heads are yellow and occur in clusters at the ends of stems.
  • Blooming Period: Australian cotula flowers throughout the year in favorable conditions, with peak blooming in spring and summer.

3. Habitat:

  • Commonly found in a variety of habitats, including lawns, gardens, wetlands, and disturbed areas.
  • Thrives in moist to wet soils but can tolerate drier conditions.

Invasiveness:

1. Invasive Characteristics:

  • Aggressive Growth: Australian cotula can be invasive, forming dense mats that crowd out native vegetation.
  • Rapid Spread: The plant reproduces both by seeds and vegetatively, allowing it to spread quickly.

2. Impact on Ecosystems:

  • Ecological Displacement: Invasive cotula can displace native plant species, affecting the structure and composition of local ecosystems.
  • Habitat Modification: Its dense growth can modify habitats, particularly in wetland areas.

Control and Management:

1. Cultural Methods:

  • Regular Mowing: In lawns and managed landscapes, regular mowing can help control the spread of Australian cotula.
  • Preventive Measures: Avoid introducing the plant to new areas through contaminated soil or plant material.

2. Mechanical Methods:

  • Hand Removal: Small infestations can be manually removed by pulling up the plants, ensuring to extract the entire root system.
  • Mulching: Applying mulch can help suppress cotula growth in garden beds.

3. Chemical Control:

  • Herbicides: Selective herbicides targeting broadleaf weeds can be effective, but careful application is necessary to avoid harming desirable plants.