This was the first plant I saw close-up when the helicopter landed on Maatsuyker Island in December 2011. Like the plant in this image, there are many growing on and above the cliff at the helipad. I know S. graminifolium and S. lineare at home in the Blue Mountains so it was a joy to see an old friend.
The reference describes the habitat as exposed sites within reach of salt spray, and this plant was right at home on the island. I saw -many- plants along most tracks. They ranged from about 5cm to 50cm high. The colour of the flowers varied from almost white to deep purple-pink. The flowers are densely packed on a “scape” (stalk growing out from the centre of the rosette of leaves).
The long flowering season spanned the duration of our visit from the start of December till early February. After the flowers die, the fruit forms – a capsule containing many tiny seeds (photo on the left).
I find this plant fascinating, especially under a microscope. I wasn’t able to take my microscope to the island, but these macro photos of S. graminifolium specimens taken in the Blue Mountains show common details. The trigger mechanism is very similar between the different species. The photo on the right shows the column (trigger) in a “set” position – bent downwards. When an insect takes the nectar from the nectar secreting glands, it brushes the base of the column, causing it to suddenly spring up.
The scape (supporting the flower) is very hairy. The botanical term “glandular-hairy” is used to describe both the scape and the corolla-tube of trigger plants. This refers to hairs with an enlarged gland at the tip. You can see this clearly in the (enlarged) macro image on the left.
An interesting history of the naming of trigger plants can be found in Vol 12 part 3 of Telopea on PlantNET. Telopea, the Journal of Plant Systematics, is published by the National Herbarium of New South Wales, Royal Botanic Gardens and Domain Trust. The article details –
Wege, Juliet A. (26 Oct 2009) Naming Stylidium (Stylidiaceae): an historical account, with specific reference to S. graminifolium and S. lineare. Telopea 12(3) : 321-332.