Wire-Leaf Mistletoe Amyema preissii has dense bunches of bright orange-red flowers which produces copious amounts of nectar, but no perfume (that I could detect) - a great example of bird pollinating flowers. However, I was perplexed by flower peculiarities.
- Stamens and pistil project out to touch a bird’s head as it drinks nectar, but petals are open right down to the ovary. This allows short-tongued insects like ants, flies, and honeybees to steal nectar without pollinating the flower.
- Flowers were open or closed with very few in between.
- In early morning nectar leaked out of closed flowers and collected on the bulbous end, but there was no sign of nectar on anthers or pistil of open flowers.
The closed downward hanging flower consists of five tepals which are fused into a long tube with a bulbous end. The anthers and stigma are packed so tightly at the end that they resist entry from nectar flowing down from the flower base.
When the flower is ready to open, nectar flows down the inside, escapes from joins between tepals on the side, and coats the end. There were lots of bees on open flowers but they avoided the nectar on unopened flowers. Didn't like sticky claws?
When I dissected closed flowers I could see that stamens and anthers form a straight line from the centre of the tepal, but the end of the tepal that encloses them is curved. This creates a spring mechanism, which is held in place by stronger join at the end of the tepal.
Perhaps, when honeyeaters lick nectar off the flower end, the motion causes the flower to spring open so the bird can pollinate it.
When the flower is ready to open, nectar flows down the inside, escapes from joins between tepals on the side, and coats the end. There were lots of bees on open flowers but they avoided the nectar on unopened flowers. Didn't like sticky claws?
When I dissected closed flowers I could see that stamens and anthers form a straight line from the centre of the tepal, but the end of the tepal that encloses them is curved. This creates a spring mechanism, which is held in place by stronger join at the end of the tepal.
Perhaps, when honeyeaters lick nectar off the flower end, the motion causes the flower to spring open so the bird can pollinate it.
About 10% of the flowers remained closed apart from a tiny dark dot on the outside, which marked the point where a moth or other insect laid an egg. Inside was a 3mm translucent grub, which ate the flower's reproductive parts then formed a dark brown pupa.
Honey bees were at the flowers from dawn to dusk with the occasional Campanotis chalceus ant. They were able to steal nectar without contacting anthers and stigma, but pollination occurred when bees collected pollen from the anthers. After seeing a bee eating pollen I learnt that honey bees have 2 stomachs: One for eating pollen and nectar for energy,and the other for storing honey for the hive.
At late afternoons a pair of large Australian Hornets buzzed in regularly to feed, and just once a Silky Azure butterfly. This was a great find as they are very rare in this district. The caterpillar larvae eat flower buds, flowers, leaves and soft stem parts of the mistletoe, but are particularly fond of the flower buds.
I decided to check out bush at Thomas Hogg Oval where Jam Wattles Acacia acuminata were infested with mistletoe (only occasional occurrence in Foxes Lair). This is typical of isolated small areas of bush. Apparently possums love eating mistletoe, particularly the flowers. As possums can't survive fox and cat predation in small areas with few trees, mistletoe gets out of control. There were lots of honeyeaters but fewer bees. Many mistletoes were old and dying back. Flowers on some were dying from extensive infestation of giant scales, which were being attended by aggressive meat ants.
Sadly an unbalanced ecosystem.
Sadly an unbalanced ecosystem.
Further information Mistletoe blog