Floral appendages include sepals, petals, androecium and gynoecium that are comprises a plant. Androecium and gynoecium are essential appendages while sepals and petals are non essential appendages . The flower is a modified shoot which possesses different floral appendages at successive nodes.

What are plant appendages?

appendage - a natural prolongation or projection from a part of an organism either animal or plant; "a bony process" outgrowth, process.

When the floral appendages are in multiple of 3?

A flower may be trimerous, tetramerous or pentamerous when the floral appendages are in multiple of 3, 4 or 5, respectively. Flowers with bracts-reduced leaf found at the base of the pedicel-are called bracteate and those without bracts, ebracteate.