Calliandra haematocephala at Cambridge Botanics
The tropical section of the greenhouse at Cambridge Botanical gardens contains many wonders, including a phenomenal example of the Jade vine (end of March), but packing a punch at this time of year (early March), due to its brilliant colour, is a red Powder Puff tree, Calliandra haemacephala. Who could resist such colour? I am seriously tempted to try to grow one just so I can touch the flowers freely.
Online information says that the seeds germinate easily after soaking, if you keep them in moist compost at temperatures of between 20° to 25°C. It might only take a couple of weeks for the first seedlings to appear! Another plus is that the plants are easily kept to a size that most suits your space (in fact they are good bonsai material). As far as I can see the only downside is the level of humidity that needs to be maintained.
Seeds are readily available. Chiltern Seeds have them at £3 for 15 seeds and Amazon have them for slightly more (promoting their bonsai use).
I remember having seen something very similar before whilst on holiday in France a few years ago. There was an eye-catching broad avenue of glossy, pinnate-leaved trees topped in candy pink and white fluffy pompoms. Obviously it’s a bit late to check now and there are ~140 species of Calliandra, but I dug out a photo and might have been Calliandra surinamensis:
Tree-lined avenue topped with pink and white pompoms
Frogend dweller's Blog 
I think your fluffy pink pompoms are Albizia julibrissin.
I went to Cambridge Botanic Gardens last week.I was disappointed that the turquoise flowers of the Jade vine in the glasshouse weren’ t out. If you go when it is out please take a photo and post it.
Thanks for your response. Albizia julibrissin does look a good fit for the photo. It also seems to be very common in cultivation in France. The stamen look more clumpy than Calliandra. Shame I didn’t get some decent leaves in the frame.
Yes, I was sad not to see the Jade vine trailing those turquoise slippers. I’ll definitely post a photo if I get back in time.