Try to make your search as simple as possible:
Specularia will find all items including that sequence of letters.
Search results for "Specularia":
"Specularia falcata" - Legousia falcata
"Specularia hybrida" - Legousia hybrida
"Specularia perfoliata" - Triodanis perfoliata
"Specularia speculum-veneris" - Legousia speculum-veneris