Sunday, August 3, 2008

Not Fruits, but Galls!

I seem to have got away with a rather conspicuous mistake in last week’s post.
The photo of Sandalwood “Fruits” was in fact a photo of some galls.
Here are some genuine fruits, from the same tree - and the red one was edible already, I discovered. I was a bit surprised to find them at this time of year.

Here is a better photo of some of the typical galls we find on our local Santalum lanceolatum.
Galls are growths on plants which can be caused by parasitic fungi, bacteria, nematode worms, gall insects, or mites. The trick is done by the plant itself, which makes abnormal growth in response to a chemical irritant produced by the parasite.
In the case of an insect gall the mothers deposit their eggs, together with a dose of irritant, in the plant tissues. As the babies hatch, the gall begins to form, with the growing insect inside it. When the baby insect reaches the right age, it bores a little escape hole. Each species of gall insect has its favourite host, which responds to it by forming galls of a characteristic shape.
Some galls (notably the “mulga apple” which forms on mulga trees) are a favourite aboriginal food. They are picked while the grub, which is considered to be delicious, is still inside.
These Santalum galls are worth a closer look, if you find some, They are quite soft and easy to cut, and may contain quite a few little grubs.

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