Merosity
![Trimerous flower of Tulipa clusiana (the three sepals resemble petals)Tetramerous flower of Correa albaPentamerous flower of Crassula ovata](/Images/godic/202502/17/Tulip_Tulipa_clusiana_'Lady_Jane'_Rock_Ledge_Flower_2000px3446.jpg")
![](/Images/godic/202502/17/Correa_Alba_RTBG3446.jpg")
![](/Images/godic/202502/17/Crassula_ovata_RTBG3446.jpg")
Merosity is the number of component parts in each whorl of a plant structure. It is most commonly used in the context of flowers, in which case it refers to the number of sepals in the calyx, the number of petals in the corolla, and the number of stamens in each whorl of the androecium. The term may also be used to refer to the number of leaves in leaf whorls.