Try to make your search as simple as possible:
Seseli will find all items including that sequence of letters.
Search results for "Seseli":
"Seseli carvifolia" - Selinum carvifolia
"Seseli chaerophylloides" - Conium chaerophylloides
"Seseli divaricatum" - Musineon divaricatum
"Seseli macrophyllum" - Mediasia macrophylla