• ​Most acacia flowers lack nectar and rely on scent and a dazzling yellow colour to attract pollinators. I think that most pollination is done by pollen-collecting bees. Birds, flies (particularly hover flies), and pollen-eating wasps may also be involved. The taxonomy literature is so confusing, I couldn't work out which subgenus a species belongs to, or their pollinators.
• Most acacias secrete nectar from special glands on stems and phyllodes (flattened leaf-like stems) to attract ants, which keep parasites away.
• Despite producing thousands of flowers, relatively few produce their pea-like pods. I suspect this may be because the seed is very long lasting and requires fire to germinate. Some seeds have a fleshy part (aril) to attract ants, which take the seed down their burrows away from predators.
• Noongars collected acacia seeds as bush tucker. A wacky friend of mine was going to make a fortune selling acacia flour noodles - until weevils crawled out of the seeds :) .

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Further reading
A Simple Botany of Wattles
Pollination Ecology of Acacias
Don't blamewattles for hay fever

Greetings fellow foxies,
About 33 years ago I planted a Eucalyptus caesia subspecies caesia (gungurru) mallee in my front yard, which has grown into a magnificent specimen that produces cascades of beautiful pink flowers. It is great bird attractant, particularly New Holland honeyeaters and western wattle birds, which claim ownership at various times of the year. Lately most flowers (and my wife's roses and geraniums) are lopped by ### twenty eight parrots. Very occasionally red-tailed black and Carnabys cockatoos chew the nuts, but not red capped parrots. Plenty of honeybees.
Eucalyptus caesia is a rare bird-pollinated species that is endemic to 25 granite outcrops in the Central Wheatbelt of Western Australia, but is widely grown in native gardens. Every surviving flower on my caesia develops into a nut even though the nearest other caesia is over 200 metres down the road, and I see the same with single eucalypt species in Foxes Lair. Evidently most eucalypts can self pollinate!

This study of E. caesia pollination at Boyagin Rock revealed some amazing information.

• The large flowers are mainly pollinated by birds, which regularly  transmit pollen up to 120 metres.
• On average there were three genetic groups at each mallee patch, which minimised damaging inbreeding. Insect-pollinated plants would have less diversity
• Clumps often had a group of clone plants which developed into individual plants as the lignotuber (mallee root) expanded then rotted between suckers. The largest  clonal patch comprised 55 stems over an area 8.8 m wide and 11.5 m long. This patch may be thousands of years old and among the oldest known eucalypts. I was impressed by the 80cm diameter root on my 33 year old plant before reading the paper.
• At natural Caesia locations, there hasn't been a surviving seedling for over 50 years. Fire is required to remove competition.
• The paper provides an opportunity to revise your knowledge of statistics and  words like cleistogamy and kurtosis.

I collected flowers at varying stages of development for examination. Pollen develops early in the flower's development, and is actively collected by honeybees as soon as the bud cap is shed, and inward-facing stamens still formed a tube down to the flower base. Soon afterwards bees crawled down into the base where nectar was being produced. Honeyeaters also started feeding as the stamens folded out and fully opened.

​ Bees vigourously wiggled their way across stamens, stuffing pollen into their leg-sacs.The anthers seemed to be sticky and didn't spontaneously shed pollen like most other flowers.

I noticed bees still licking nectar from the flower base in mature flowers while anthers were declining. This indicated that the later maturing stigma on the end of the style was still receptive to pollen. It is a logical way to prevent the flower pollinating itself.
Signs of stigma maturity were subtle, but images show it changes from being hidden in the bud cap,then a fold at the tip (non-receptive), to a moist receptive bulge.

​Honeybees are larger than most native bees, but it was evident that they rarely contacted the stigma due to large flower size. They just stole pollen and nectar while birds, small animals, (large flower wasps?) did the pollination. Red flowers are much more visible to birds and large animals than insects.
Apart from stink bugs, which routinely remove growing points from most seedlings I try to rear in Foxes Lair, few insects bother my street tree. This little fellow is tolerated.