"Mal." is likely Malayalam, a dravidic language from the indian subcontinent, not Malay (Austronesian language).

My Latin is quite rusty, its been a long time since i studied it. But from what i remember there were several flavors, which had slightly different grammar, orthography and vocabulary.

Wikipedia confirms this - there is at least classical Latin, church Latin, New Latin (16-19c), Contemporary Latin (19c onward). Hortus Malabaricus is written in New Latin.