I recall some discussion of the effects of plane tree pollen on some members of the population in southern Australian newspapers. I saw it for myself a few years ago when in Melbourne, Australia. My husband and I were hurrying to catch a tram and by the time we were on board he was red faced and straining for breath. He sounded like he was having an asthma attack, but his restricted airway released as we headed away from the city. Tens of minutes later, the seaside air of St Kilda revived him. The symptoms returned when we went back to the city hotel; fortunately not so severely. The only trigger we could discover was plane tree pollen - it was falling in visible drifts that weekend. What a pity such robust and attractive trees have this effect.
Wow, that sound kind of scary. I'm sure glad all ended well.
I guess such a huge tree must produce amazing amounts of pollen. I think I read that each seed ball can have 800 seeds.
Thanks for reading and adding to the story!