A million blooms, more or less

I took a picture of this Backhousia myrtifolia late last year, in Melbourne Gardens (Royal Botanic Gardens Victoria) posting it on social media with a lament about it's underselling common name, Grey Myrtle. I also noticed, when I took the following close up, that there were a mighty lot of flowers on this tree.

My very rough estimate, based on extrapolating from the number between my thumb and forefinger, then multiplying that unit ten fold, then ten fold again, was one million. Give or take tens of thousands I presumed.

Colleagues Neville Walsh and Andre Messina did a recount later in the same day and came up with 800,000 and 300,000 respectively. The average of our three estimates is 700,000 flowers.

This waratah growing in the Blue Mountains Botanic Garden at Mount Tomah, Telopea 'Shady Lady' I think (possibly the one in my photograph above!) had reputedly 500 or so blooms a decade ago. Each bloom contains a couple of hundred flowers (let's say 200), so all up that's 10,000 flowers.

Which happily is the same number claimed for the Ten Thousand Flower Camellia (above) growing in a temple in Lijiang, in southern China. I saw it on my first visit to China, in 2004. Although as you can read on this sign, it's actually two different cultivars of Camellia (hence two kinds of flowers in the picture above), fused together. So perhaps we should score this one as 5,000 flowers a piece.

Which got me thinking about what would be the most flowers you might get on a single plant, or let's say tree or large shrub. Could it be a woody daisy, given a single flower head might contain many  flowers?

No sooner had I suggested this than Neville Walsh pointed out a two-metre high specimen of the Victorian native daisy, Cassinia trinerva, growing in the Australian Forest border of Melbourne Gardens. While its flower heads (the pointy white bits below) each only contain only 3 or 4 flowers, there are a lot of them.

Each 'compound inflorescence' (in focus above) might contain 1000 of these tiny flower heads, each with lets say just 3 flowers, and there might be 250 of them on the bush. That would tally up to 750,000 flowers. My one-minute very rough estimate in front of the bush was 1.3 million flowers. Neville thought more like 1.5 million.

And what about cherry blossom trees, laden with pink petals? Or perhaps the tallest flowering plant in the world, a Tasmanian Mountain Ash (Eucalyptus regnans) measured recently at 100.5 metres high. How many flowers would it produce in a good season?

In my local street and gardens there are lots of floriferous trees: the Cape Chestnut (Calodendron capense), privets (Ligustrum species) or the local Sweet Bursaria (Bursaria spinosa)?

According to a Pinterest post (yep), an avocado tree can produce a million flowers in a season. So if we extend our counting to a flowering season rather than a particular day, that might allow a few other species into our list.

So, any thoughts? Or better still, evidence?