Not a rare item so it is somewhat inexplicable that you haven't seen it for sale there.

also known as the dumb cane ...

just fyi ... its poisonous ... so dont put it in a situation where something might happen ...

https://duckduckgo.com/?q=Dieffenbachia+species+poisonous&t=ffcm&ia=web

many things are ... so dont freak out... just be safe ..

that said.. it is gloriously grown ... i hope you can keep that going ...

i doubt the age claim ... but there are easily rooted and regrown ... i suspect.. over the decades ... that is what he did ... and he was real good at it ....

ken

The OP did say " growing, pruning, and "propagating" , Ken.

Thank you for the comments. The photos I posted is the propagated version but the parent was about 8 feet. Here’s a pic of the parent before it got pruned (sorry for the bad quality)

It's most likely Dieffenbachia seguine, although they don't usually get that tall when grown indoors in pots.

That's a beauty! They do normally have long lifespans, and yep, they can be renewed practically eternally. Thirty is exceptional, but if I can keep an indoor hibiscus going for 22 years and counting, then I believe 30 and counting with no problems.

I like Dieffenbachias too, but even skin contact with the leaves will cause temporary skin dermatitis (at least they do in me), but that does not stop me from growing any poisonous or toxic plant. I don't like their natural legginess so I periodically make cane cuttings (in the humid summer).

This one got all stretched out and hit the ceiling because the room was too dark for it.

Tropic snow! This one was given to me almost 2 years ago and while moving it two canes broke off so they were propagating and groaning beautifully.

"propagating and groaning beautifully"

Would I really want a plant that makes that much noise, though? :-)

Will try to send pic, technical difficulties!