pentamerous

A flower in which the parts are arranged in twos is called dimerous; when the parts of the whorls are three, four or five, the flower is trimerous, tetramerous or pentamerous, respectively.

In the large tropical genus Croton a pentamerous calyx and corolla are generally present, the stamens are often very numerous, and the female flower has three carpels.

Thus, in both Lilium lancifolium and L. auratum the writer has frequently met with pentamerous flowers.

The symmetry which is most commonly met with is trimerous and pentamerous—the former occurring generally among monocotyledons, the latter among dicotyledons.