Tag Archives: Stylidium productum

Trigger Plant

Stylidium productum

“A tufted herb with grass like leaves, found in moist forest situations.”NPOS p.219

The trigger plant has developed the fascinating ability for movement fast enough to outdo animal reflexes. The trigger plant’s pollen producing anthers are located at the end of a stalk emanating from the center of the flower. The stalk is cocked back behind the flower like the hammer of a gun. When an insect lands it triggers the hammer which crashes onto the insect, showering it with pollen. The insect then flies away to fertilize the next trigger flower it lands upon. The flower resets itself in 20 minutes, ready for it’s next customer.

There are several species of trigger plant found in the Sydney area, I’m reasonably confident this is the Stylidium productum. It was found on a moist hill side atop Hawksburry sandstone. Stylidium productum is a small herb like plant consisting of a single stem, leaves are grass like and grow directly off the stem. Flowers grow at the end of a stalk that comes out of the top of the plant. We’ve got a few of these in the yard but they usually get munched by rabbits or wallabies before they get a chance to flower.

Trigger Plant
Leaves of the trigger plant. The long flower tipped stalk grows out from the top of the plant.
Trigger Plant flowers
The purple flowers of the Trigger Plant. Each flower has a hammer cocked and waiting to be triggered by the next insect that lands on it.
Trigger Plant Flower
Trigger Plant Flower locked and loaded. The arrow traces the arc of the hammer.