The sterile leaf organs of the flower build the perianth and are referred to as perianth-leaves. The perianth often consists of morphologically different sepals and petals (cf. heterochlamydeous perianth e. g. in Rosa – Rose). If the sepals and petals are of similar habit (e. g. in Tulipa – Tulip) or if only whorl of perianth-leaves is developed (e. g. in Scleranthus – Knavel), they are referred to as tepals. Occasionally, sterile and petal-like stamina (staminodia) are involved in assembly of the perianth (e. g. in some Ranunculaceae – Buttercup family members).