h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I was given a huge cactus for Christmas and had no idea when to properly start watering it, and now I know it should be about now. I've had cacti before, and most have survived my ignorance, so hopefully things shouldn't go too wrong with this one

You're very welcome. Did you cactus come with a label telling you what species it is?

No, it's my grandfather's multi county show prize winning cactus which he has grown for at least 25 years and he just gave me a list of unhelpful instructions including 'keep away from small children', 'do not tilt at an angle greater than 4 degrees' and 'not suitable for human consumption'. If he knew the species he wouldn't tell me, he's the sort of person who prefers to challenge you to find out

Ah. Did he also say 'No user serviceable parts inside'?

Let's do this the hard way then. Tall or globular?

No, must be about the only possible warning label he missed out. Not tall, so must be globular. Lots of cylinders, some with 'arms', none more than about 30cm tall. Has a furry look but definitely has spines, took some time after unpacking it to get them out of my jumper.