It's all because people were too embarrassed to pronounce it properly, as FOOKS-ya. Named after a fellow named Fuchs.

The tropical flower Rafflesia is another one I always find difficult: my internal grammar wiring insists it must be pronounced ra-FLEES-ya. But that makes no sense of either the original English name Raffles, or any Latin translation of it.

And of course Monsieur Magnol never gets his name pronounced properly by English speakers :-)