Try to make your search as simple as possible:
Coriandrum will find all items including that sequence of letters.
Search results for "Coriandrum":
"Coriandrum sativum Cilantro Sa" - Coriandrum sativum Santo Cilantro organic seed
"Coriandrum testiculatum" - Bifora testiculata
"Coriandrum tordylioides" - Coriandrum tordylium