Try to make your search as simple as possible:
Gazania will find all items including that sequence of letters.
Search results for "Gazania":
"Gazania krebsiana O P" - Gazania Orange Peacock rs
"Gazania splendens" - Gazania rigens v rigens
"Gazania splendens D M" - Gazania rigens Dwarf Mixed rs
"Gazania splendens mixed" - Gazania rigens Mixed cs
"Gazania splendens Sunshine M." - Gazania hybrida Sunshine Mixture bs