It's an emulator problem that was introduced in the newer versions of ZSNES when they removed a hack that made them display correctly.
Timing issue, not hack.
I'm with JCE on this. It was hump a wall time back in the day.
There's also the one that JCE mentioned in Mist..
There's also the Blacksmith's place, directly east of the stairwell. However, for some fucking lame reason it was removed in FF4A (like the Ether at Rosa's House).
Don't forget the two Carrots in the large Chocobo forest and the hidden items in Silveria. And the hidden chest in Baron's waterway passage.
It's 3 total IIRC, the Carrots north of Troia.
I also think JCE meant to say blacksmiths... because the Adamant Grotto is the tail trading place.