Try to make your search as simple as possible:
Sutherlandia will find all items including that sequence of letters.
Search results for "Sutherlandia":
"NOT syn. Sutherlandia frut." - Lessertia frutescens
"Sutherlandia frutescens" - Lessertiaia frutescens
"Sutherlandia montana v procumb" - Sutherlandia frutescens Prostrata