Asked to name a parasitic plant, most of us probably think of mistletoe.
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We have several other native parasitic plants, including three species of twining creepers known as dodder-laurels.
The smallest dodder-laurel, with the finest stems, is pictured here. This is the slender dodder-laurel (Cassytha glabella), photographed in the Woowookarung Regional Park at Canadian.
This specimen was twining around the leaves of austral grass tree, a prominent feature of the park. The "suckers" of the parasitic twiner can be clearly seen, grasping onto the stiff, angular grass-tree leaves. There are also a couple of developing fruits on the right of the picture.
The dodder-laurels (of which there are three species in the Ballarat region) are virtually leafless. They climb on, and parasitise, small plants, trees and shrubs.
Young plants are green at first. Their stems contain chlorophyll, but, once the dodder-laurel plant is fully established on its host, it loses much of its green colour and becomes yellow or orange, and no longer needs its roots.
They are not selective in attaching to a host. A stiff grass tree leaf, as shown in the photo, might seem an unlikely subject when compared to a normal leafy plant.
A single stem may attach itself to several host species as it grows and twines. Sometimes a stem may turn back and parasitise itself.
Our three local dodder-laurel species are - conveniently - small, medium and large. The photo shows the smallest, with thread-like stems. It twines and tangles among smaller plants, seldom growing much more than knee-high.
The largest species, known as the coarse dodder-laurel, has string-like stems sometimes two or three millimetres thick. It can grow several metres tall, smothering shrubs and sometimes small trees as it goes.
A dodder-laurel plant will die when its host plant dies.
Our local species have tough, flexible stems, which were used by Aboriginal people - and probably early European settlers - for string.
The fruits of some species are succulent and are eaten by birds.
GREY BOX
This eucalypt is flowering prolifically across north-central Victoria, but its flowers are not attracting lorikeets and honeyeaters.
The sound of bees and other insects in the flowers indicates that pollen, at least, is being produced, but the absence of birds means that nectar is scarce or absent.
A study of flowering ironbarks showed that the trees did not produce honey until there had been a few cold nights. Perhaps this will happen with the grey box.