Mimicry in the Making at Crocodile Point, Toronto: Mistletoe and Myth

By Landcare Support Officer, Amy Trello  

Landcarers spend a good amount of time close to the ground with their head and hands in the weeds. On a similar occasion at Toronto Lions Park West (aka ‘Crocodile Point’ to the local Landcare volunteers), while taking a break from weeding, I stood up to stretch my back and look up at the Casuarinas trees above.  I noticed some sort of distorted branching in the tree. What could this be? On closer examination I felt these spongy leaves and observed unique burgundy flowers that were clearly not the leaves and flowers of Casuarina. This was in fact a native mistletoe. It was mimicking the leaves of the Casuarina glauca. Aren’t plants fascinating! I knew this was a type of native mistletoe because of a workshop I had participated in through Local Land Services and Bird Life Australia in the last couple of years.


Can you spot the Mistletoe?




Left: Swamp she-oak (Casuarina glauca) Right: Needle-leaf mistletoe (Amyema cambagei)

There is a common myth mistletoe is bad and it kills trees. This is not entirely true. Tree health often declines due to a combination of factors. Trees are complex organisms and have ways of defending against pests and pathogens. Trees in bushland areas rarely die because of mistletoe infestations. I recall having a conversation with a farmer in the Hunter Valley who stated the area was once known as Mistletoe Valley and mistletoe killed off trees. It is now known agriculture and land clearing practices play a significant role in tree decline; rather than mistletoe.

Mistletoe are hemiparasitic (half parasitic) meaning it grows on a host tree or shrub. Most hemiparasitic plants grow below ground level unlike mistletoe which grow above ground. They attached to the host via a root like swelling called a haustorium.  Generally speaking mistletoe take only the water and nutrients it needs from its host. It needs its host to thrive so that it can survive. There are over 1500 mistletoe worldwide and 97 identified Mistletoe are native to Australia. They perform a plethora of ecosystem services and serve as an important piece in biodiversity.

Some Facts Surrounding Mistletoe

  • Native birds, gliders, possums, other herbivores and insects use it as food and shelter.
  • 27 identified native butterflies use them as a host to lay their eggs.
  • Many Australian birds have been seen nesting in Mistletoe.
  • Its ample leaf litter is full of nutrients and are important for soil health.
  • They are described as a keystone species meaning it enables other species to survive.
  • There is mistletoe that actually grow on mistletoe.
  • Mistletoe are aerial-parasitic meaning it grows on a host tree or shrub taking its water and nutrients only taking what it needs from its host.

The next time you take a moment to relax amongst your site see if you can spot this important little plant performing a big function.

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