Try to make your search as simple as possible:
Stereoxylon will find all items including that sequence of letters.
Search results for "Stereoxylon":
"Stereoxylon pulverulentum" - Escallonia pulverulenta
"Stereoxylon resinosum" - Escallonia resinosa
"Stereoxylon rubrum" - Escallonia rubra
"Stereoxylon virgatum" - Escallonia virgata