Try to make your search as simple as possible:
Iresine will find all items including that sequence of letters.
Search results for "Iresine":
"Iresine glomerata" - Pfaffia glomerata
"Iresine javanica" - Aerva javanica
"Iresine paniculata" - Iresine diffusa
"Iresine persica" - Aerva javanica