The China rose is a type of hibiscus that is native to Asia, particularly the warm or tropical areas of the continent. The flowers of China roses grow up to eight inches in diameter and are trumpet shaped. The flowers have several unique characteristics that separate them from other members of genus hibiscus, including arrangement of flower components and the number of petals.
The pistil, regarded as the "female" part of the flower, consists of the stigma, style, ovary, and ovules. In a China rose, the pistil is prominent and centrally located. The style is the very top of the pistil and is slightly sticky in order to allow pollen grains to adhere. Once trapped, the pollen grains move down the tubelike style to the round ovary, which contains the ovules. The ovules and pollen grains fuse to form the precursor to another plant.
The stamen is the "male" part of the China rose and consists of the anthers and filaments. The anthers contain yellow pollen grains and are located atop the stalklike filaments. In a China rose, the filaments are fused in a bundle around the style, while the anthers remain unbound and encircle the stigma. The fact that the filaments are fused and the anthers are free makes the China rose a monadelphous plant.
Petals and Sepals
Although China roses are capable of self-pollination, each flower has five large, flat petals that are brightly colored to attract pollinators. The pistil and stamen project beyond the plane of the petals to allow for pollination by flying insects and birds. The petals of China roses have overlapping edges, this is called a contorted arrangement and gives the flowers their characteristic trumpet shape. The sepals are small leaflike appendages that enclosed the flower when it was a bud and remain vestigally in adulthood.