Activity Around the Trigger Plant!

 

A small winged insect hovering around the bloom of Stylidium debile AKA Fragile Trigger Plant

    I was tending to some carnivorous plants when I noticed, a tiny winged insect flying around the bloom of a Stylidium debile (AKA Fragile Trigger Plant).  That's the plant in my post from April 30, 2025 (click to see post), where the reproductive column "smacks" an insect when it is triggered, transferring pollen to the insect as part of the reproduction process.  I watched as the tiny winged insect landed in the middle of the bloom and triggered the reproductive column!  It was fun to watch and it looked like the column gave the insect a 'one arm hug'! It held for a few seconds and the insect didn't seem to be bothered by the action.  Oh I wished I had my camera with a close-up lens to capture that moment.

After a minute or two, the column reset and the insect returned to enjoy the bloom, but it didn't trigger.  After some observation I learned that after resetting, there is about a 15 minute window before the column smacks again.  The picture below is with my iPhone and after the insect got "smacked".

A small winged insect on the bloom of Stylidium debile AKA Fragile Trigger Plant

An Amazing Plant - Stylidium debile! (Frail Trigger Plant)

Stylidium debile AKA Fragile Trigger Plant

     Last fall I received several Stylidium debiles (AKA Fragile Trigger Plant) from my friend Diane Dunhill.  It grows in a bog environment and is a good companion plant for my sundews and American pitcher plants.  It's very small and I placed an American penny (2 cm in diameter) in the picture for scale.

Stylidium debile AKA Fragile Trigger Plant

     It's native of Australia and is much debated because during the flowering season it's flowers become sticky traps for insects making it carnivorous.  Look closely and you can see the tiny tentacles with mucilage on the back of the buds and scape.  Because this plant is not carnivorous year-round, it is often considered proto-carnivorous. But that is not the amazing part.

Stylidium debile AKA Fragile Trigger Plant

     What makes this plant amazing is the unusual method of smacking insects with their pollen. In the center of the flower is a touch-sensitive trigger that sends the column quickly flying toward the insect and upon impact, the insect will be covered in pollen and stunned, but not harmed. 

     Because the column comprises the fused male and female reproductive organs of the flower, the stamen and stigma take turns in dominating the function of the column.  The anthers develop first and then are pushed aside by the developing stigma. This delayed development of the stigma prevents self-pollination and ensures that cross pollination will occur between individuals of a population.

I made a video and used a wooden skewer to trigger the smack!

This second video is slow-motion (1 tenth the actual speed) of the smack.  As you can see, it's really a fast smack.

This last video shows the column of the bloom resetting.  It takes about 2 minutes for the reset and this video has been sped up to show the movement in 21 seconds.

Stylidium debile, after the slap on the left and on the right it's reset and ready to slap again!