Young Brunette Girl Outside In Yellow Flowers

A flower is a modified stem tip with compressed internodes, bearing structures that are highly modified leaves. In essence, a flower develops on a modified shoot or axis from a determinate apical meristem (determinate meaning the axis grows to a set size).
Flowers may be directly attached to the plant at their base (sessile--the supporting stalk or stem is highly reduced or absent). The stem or stalk subtending a flower is called a peduncle. If a peduncle supports more than one flower, the stems connecting each flower to the main axis are called pedicels. The apex of a flowering stem forms a terminal swelling which is called the torus or receptacle. The parts of a flower are arranged in whorls on the receptacle. The four main whorls (starting from the base of the flower or lowest node and working upwards) are as follows:
• Calyx: the outermost whorl consisting of units calledsepals; these are typically green and enclose the rest of the flower in the bud stage, however, they can be absent or prominent and petal-like in some species.
• Corolla: the next whorl toward the apex, composed of units called petals, which are typically thin, soft and colored to attract animals that help the process of pollination.