pseudevarnia, corrected
heard as pseudevarnia
spelled pseudevernia
Pseudevernia. The stressed syllable is vern, with an e.
What the ear did
An r after a vowel swallows it: vern, varn and vurn are hard to tell apart in speech. The e belongs to Evernia, the genus this one is named against, so it stays.
P-S-E-U-D-E-V-E-R-N-I-A
The full entry for pseudevernia covers the name itself.