Someone has been very thorough in their vandalism at the Botanic Gardens. It amazes me that anyone would make the effort to ensure their edited version of the sign would be consistent. But this is bugger all damage compared to the theft of rare and notable succulents from the Arid Garden. (A problem we've also had at work, with one or more thieving bastards taking agaves and other plants from the garden we've set up for teaching botany.)
Larcenous collectors are probably the reason that there are few plant IDs in the Arid Garden. I suspect it's not because people nick the labels but that they're not cluey enough to identify the plants without assistance. No labels, no theft*. (And I like to think that collectors who are knowledgeable wouldn't steal from the RBG. I could be completely wrong.)
It was great fun wandering through there with a botanist who could not only put names to the cacti and succulents but also talk about their ecology and biogeography. (And not feel inclined to dig them up and shovel them into a backpack.)
Unfortunately, I didn't write down any of the identifications because I was too busy taking photographs and being amazed. So here are some views of the garden.
*Large cactus are labelled. They have their own defence against thieves.