I took this pic in the same area a few months ago, thinking it was the same plant, but evidently not. Not one I'd like to run into on a dark night!

The first one is a Cereus, maybe C. repandus, as is the second one, but different species. But maybe the second one is a Trichocereus. Or are they?

Anyway, long story short - they're both South American columnar cactus, flowering (white) at night, and their fruit is edible / delicious. It's also known that they contain shamanistic qualities.

They're great-looking plants. If you think to water / fertilize them when you can, they'd appreciate it, but they can grow quite well on short rations when they're adapted to their environment.

Frog Rock, Australia - at first I thought these plants might be in the high desert east of San Diego or the like. Well, it is like that.

Thanks for that info, cactusmcharris.

Unfortunately, I won't be watering or fertilising this one. It's about a kilometre from my house in a difficult to access area that I only visit when I'm cutting firewood. It appears to be surviving quite ok on its own devices, having suffered through the last 3 years of drought, where a couple of hundred of my mature trees (20 metres+) curled up their toes.

This isn't the first "stranger" to pop up on my place. You may remember this old post of mine from years past...

Query From 2015

Sorry to hear about the trees, shax, but it definitely, if not piercingly, demostrates the power of cactus. Fascinating that a plant of the Andean highlands can naturalize where it did, but I guess it proves that your environment is definitely within the range of its liking.

Have a cup of Bushell's for me. But you also have to promise to drop in more than once every five years.