The Hendon Fungus, a kids' read from yore

In Standard Four at primary school, I had the worst teacher ever She was just horrible, in the way that some teachers are when you're a kid. I may have actually hated her.
I remember several things about Mrs Matthews. She was old. (Probably my age now, tbh)
She smoked. I have a recollection of packets of Benson and Hedges, something gold, on her desk, in the larger packs. She had a smoker's voice so the smokes didn't kill her off early. She lived well beyond retirement age. She taught us our times tables. I really doubt anyone left that class at the end of the year not knowing at least up to the ten times. I know adults to this day who couldn't tell you off the top of their heads 9 x 8 or whatever.
And she read the class, The Hendon Fungus.
I have just re-read the book. I've read it a few other time since I left primary school and I love it. It is funny, it has great characters, it is science-fictiony.
It is probably my most favourite kids book ever, and I remember Mrs Matthews reading it to the class and being so gripped by it, that I am sure I took it out of the school library, and read it again.
It involves some heroic kids whose father is a scientist who brings a strange fungus back to England and they plant it, as he instructs them. Except this fungus grows and multiplies and basically... I will say no more.
I doubt there are many copies of this book in too many libraries now (it was written in 1970) but if you feel like a fun read, I say, give it a try.  It is fiction and there are some things that don't ring true. But it is fiction, and there is a lot of humour in it, given its a very dire apocalyptic topic.
Six out of five stars.