What is "diastella"

Diastella is a genus containing seven species of flowering plants, commonly known as “silkypuffs”, in the protea family. The name comes from the Greek diastellein “to separate”, with reference to the free perianth lobes – the plants are distinguished from the closely related and similar leucospermums by the possession of four free perianth segments. The genus is endemic to the Cape Floristic Region of South Africa where it has a very limited range and is associated with fynbos habitats. The species are all small shrubs. Most species are threatened.