Psidium cattleyanum , commonly known as Cattley guava, strawberry guava or cherry guava, is a small tree in the Myrtaceae (myrtle) family. The species is named in honour of English horticulturist William Cattley. Its genus name Psidium comes from the Latin psidion, or "armlet." The red-fruited variety, P. cattleyanum var. cattleyanum, is commonly known as purple guava, red cattley guava, red strawberry guava and red cherry guava. The yellow-fruited variety, P. cattleyanum var. littorale is variously known as yellow cattley guava, yellow strawberry guava, yellow cherry guava, lemon guava and in Hawaii as waiawī. Although P. cattleyanum has select economic uses, it is considered the most invasive plant in Hawaii.