I researched this a bit and it looks like the actual slur is "Kaffir", which is also spelled "Cafri" and comes from the Muslim term for "non-believer". And somehow this word was chosen to be used as a slur and is considered highly offensive in South Africa. As an American, I'll draw a similarity with the "N" word.

But is the plant name racist in the sense that when they named it, they were picking the slur purposefully? Or does the word simply _sound_ like the slur?

Even the latter can be enough if you consider what it would be like if name had the "N" word - or even something that had the same sound. You would literally be unable to use the plant name out loud. But it would be important for publications covering this to not call it a "racist plant name" as that really depends on how the name was given.

https://en.wikipedia.org/wiki/Kaffir_(racial_term)?useskin=v...