patana
A type of open, hilly grassland, especially in Sri Lanka, often formed after the clearing of jungle.
A considerable area of the jungle vegetation (rain forest) of the montane zone has been destroyed and is now either tea plantation or native patana grassland.
Where it comes from
From Sanskrit पतन (patana). The spellings patina and patena are probably by conflation.
Adapted from the Wiktionary entry patana (CC BY-SA 4.0).