Try to make your search as simple as possible:
Myagrum will find all items including that sequence of letters.
Search results for "Myagrum":
"Myagrum alyssum" - Camelina alyssum
"Myagrum paniculatum" - Neslia paniculata
"Myagrum rugosum" - Rapistrum rugosum
"Myagrum sativum" - Camelina sativa