Dune Weeds

Some plants, usually imported from other countries, have become serious pests. The worst ones are very aggressive, crowding out native species and causing many other problems.

• Boneseed (Chrysanthemoides monilifera) is a busy that grows about 3 metres high. The seeds are very hard and bony. In September and October, it produces bright yellow flowers. It grows on stabilized dunes and can become so thick that nothing else can grow there. It grows so fast and thick that it even makes access to the beach difficult.
  
  
• Pampas looks like the native toetoe, with tall upright stems with bushy white or purple flowers on the tops. It is a grass that grows in large clumps up to three metres high. Pampas grass has upright heads that are purple or yellow-green while the native toetoe flowers droop downwards and are a rich creamy yellow.
  
  
• Boxthorn (Lycium ferocissimum) has nasty long, sharp, poisonous spines along it's stems. It grows in thick clumps, and restricts access to beaches while pushing out native plants.
  
  
• Shore wattle (Racosperma sophorae) was introduced to New Zealand from Australia to help revegetate sand dunes. Unfortunately, it did so well it became thick masses up to three metres tall, rapidly displacing all native dune vegetation along with native birds, insects, and snails. It is very difficult to remove, but in the Waikato, the Whiritoa Beach Care group has removed large areas of this invasive weed.
  
  
• Marram grass (Ammophila arenaria) was another plant introduced to revegetate sand dunes (will the government never learn?). It forms steep, stable dunes too close to the water and these often blow out during bad storms. It also pushes out pingao and spinifex, reducing the populations of these valuable plants.