It does not matter if ones interaction with cacti is just recognising them as spiky plants that more than likely will hurt you with the slightest touch or one is seasoned cacti collector, you've definitely seen Echinocactus Grusonii at some point. It is not a surprise – this cactus has been known to us for over 130 years. This massive specimen was an instant attraction in cactus world. Big, spiny and not that hard to look after, it grows from 20cm to 130cm in diameter and can reach up to 1m in height.