Tuesday 15 November 2011

Triggerplants in Western Australia

Anstey-Keane Dampland, Western Australia

Book triggerplant Stylidium calcaratum

If you look closely you will see the 'trigger' between the petals on the right hand side, curled up; it is rather feathery at the tip. In fact, I've learned that it is the fusion of both male and female reproductive organs which develop at different stages to avoid self-pollination. The trigger will flip over a visiting insect and that way the pollen will travel to another plant or/and get pollinated in the process. Then the trigger will flip back to its resting place.
This is the most amazing mechanism. These flowers are very touchy and people have taken videos, do search around...
I took pictures of another trigger plant is the same reserve.

Stylidium perula
Not such a good picture but the trigger is there, curled to the left. But if you look closely at the bud in the above picture you can see shiny specs on it and along its stem. These are special glands and they can trap small insects which the plant will digest. This is called protocarnivory; see here for a detailed explanation http://en.wikipedia.org/wiki/Stylidium#Carnivory
This type of carnivory is another fascinating fact about these sophisticated plants. It reminded me about recent research with teasels. Apparently they can digest the plants that fall in the water accumulated at the base of their leaves; another kind of carnivory. 

It is no coincidence that triggerplants share their habitat with sundews - very poor moist soil - and we saw them there as well: two species: the pygmy Drosera and the redink sundew.
I would have overlooked them all if it weren't for Bryony Fremlin and David James who gave us a guided tour of this wonderful dampland. As it is, afterwards I have had a lot of fun 'discovering' triggerplants and blogging about it :-) 

Other links:

http://www.flickr.com/photos/jean_hort/6384203809/in/photostream/- for a series of excellent close-up pictures of the S. perula trigger by Jean Hort
http://www.gdaywa.com/wildflowers/triggerplants.php - for a great collection  of trigger plant photos
http://florabase.dec.wa.gov.au - for serious botanical information
Carnivory in the Teasel Dipsacus fullonum — The Effect of Experimental Feeding on Growth and Seed Set

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