lyounularia and the y sound at the front
heard as lyounularia
spelled lunularia
The y is heard and not written. Lunularia.
What the ear did
Older British pronunciation puts a distinct y glide after l in words like lunar and lucid, so the first syllable can arrive at the ear as lyoo. There is no letter for it here; the u carries the whole thing.
L-U-N-U-L-A-R-I-A
The full entry for lunularia covers the name itself.