Try to make your search as simple as possible:
Gynandropsis will find all items including that sequence of letters.
Search results for "Gynandropsis":
"Gynandropsis gracilis" - Podandrogyne gracilis
"Gynandropsis gynandra" - Cleome gynandra
"Gynandropsis pentaphylla" - Cleome gynandra
"Gynandropsis speciosa" - Cleome speciosa