merchantia, the name that looks like a word
heard as merchantia
spelled marchantia
Marchantia, with an a. The word inside it is a name, not the word merchant.
What the ear did
This is the one liverwort name that turns into an ordinary English word if you let it. The surname Marchant and the trade word merchant are close in sound and close in origin, but only the surname is in the plant, and it keeps its a.
M-A-R-C-H-A-N-T-I-A
The full entry for marchantia covers the name itself.