Try to make your search as simple as possible:
Hiraea will find all items including that sequence of letters.
Search results for "Hiraea":
"Hiraea anisopetala" - Alicia anisopetala
"Hiraea macroptera" - Callaeum macropterum
"Hiraea pubiflora" - Mascagnia pubiflora
"Hiraea rigida" - Mascagnia rigida