Lechenaultia formosa, Red Leschenaultia is one of my favourite wildflowers. Partly because the patch I irrigate and till in Foxes Lair rewards me with exquisite flowers that remind me of mini red Manta Ray heads (yep I am a dreamer!)
The 'tongue' is an indusium - a cup at the top of the style and surrounding the stigma that collects pollen from the anthers while still in the bud. It is another example of secondary pollen presentation, which is used by many Australian plant species to ensure precise pollen placement, and is a feature of the Goodeniaceae genus.
In the images below I have cut petals away to show the process involved in loading and presenting the pollen as a flower develops.
Stamens are joined in an anther ring (connate) halfway up the unopened bud. The cupped indusium grows up to the anthers and collects pollen before growing through them to the mouth of the flower.
The 'tongue' is an indusium - a cup at the top of the style and surrounding the stigma that collects pollen from the anthers while still in the bud. It is another example of secondary pollen presentation, which is used by many Australian plant species to ensure precise pollen placement, and is a feature of the Goodeniaceae genus.
In the images below I have cut petals away to show the process involved in loading and presenting the pollen as a flower develops.
Stamens are joined in an anther ring (connate) halfway up the unopened bud. The cupped indusium grows up to the anthers and collects pollen before growing through them to the mouth of the flower.
 Late bud stage |  Indusium grows up to receive pollen from anthers above |  Indusium grows through anther ring |
As the flower opens the indusium bends to present a package of pollen to insects that presumably crawl in to find nectar.
After the pollen has been removed or dies, a white growth of stigma cells emerges on the side of the indusium to harvest pollen from visiting insects. Voila, pollen delivered and collected from a precise spot on the target insect's body!
After the pollen has been removed or dies, a white growth of stigma cells emerges on the side of the indusium to harvest pollen from visiting insects. Voila, pollen delivered and collected from a precise spot on the target insect's body!
 Flower almost open when dissected |  Flower open |  Fully open, stigma has appeared |
Indusium shapes vary and could remind one of the human eating plants in 'The Day of the Triffids' novel. The one on the common Lechenaultia biloba, Blue Leschenaultia is a ripper. Last year I found dainty little Lechenaultia tubiflora in deep white sand at Ockley Nature Reserve.
 Lechenaultia biloba |  Dissected Lechenaultia bilobas |  Lechenaultia tubiflora |
Here are more Goodeniace examples.
 Scaevola species |  Goodenia etheira |  Goodenia scapigera |
Goodenia caerula appears to be an exception because an insect has to push through closed petals to find the indusium. I suspect that this could be a moisture saving aid because this species flowers on gravel soils in November.
 Goodenia caerula. Bright yellow centre to attract insects. |  Goodenia caerula partly dissected |  Goodenia caerula indusium and stamens |
On the other hand all Dampieras also have hidden indusia, but in a small fold in two petals and called an auricle.
Typical Dampiera flowers
Genus Anthotium also hides the indusium in an auricle. Dainty priority 3 threatened species Anthotium odontophyllum, Durells Anthotium flowers on clay soils at the Claypit in November.
Anthotium odontophyllum note raised auricles