We are on a war footing.
The enemy is all around us.
This enemy is probably somewhere on your street, if not lurking in some corner of your very home, waiting for a chance to strike.
We must do all we can to combat this enemy, this accursed blight on our civilisation.
We must banish it, destroy it, see it consumed in the fiery depths.
But we must not crush it beneath our heel, because that would really hurt.
The enemy's Latin name, tribulus terrestris, makes it sound like an earthly tribulation, a terrible trial for the whole world to face.
But you would know it by another name.
Its name is Jack.
Three-corner jack, to be precise, or caltrop.
Some friends used to rent a place they called the prickle palace.
Every time you went to visit, your shoes and your tyres and anything else that might have brushed against the ground would come up covered with the darn things.
As most of you would know all too well, those prickles don't tickle when you find them with the ball of your foot in the dark at one in the morning.
So this is a call to arms, a rousing message urging action against our common foe.
Councils, NRM boards and other earthly powers can only do so much against it.
Only by enlisting our help, with the aid of every patriotic Australian, can this enemy be defeated.
You will know it by its fern-like leaves, silver on the underside, which spread from a central stem; and by its small yellow flowers or spiny burrs.
A single caltrop burr may contain up to 20 seeds, so a single plant may produce thousands, and each seed may lie dormant in the ground for several years.
So we must be vigilant, and carefully pull them out.
Herbicides are also available, though several applications may be necessary as they keep coming up following summer rains.
Go forth and do battle, for the sake of our children and our children's children.