Young Brunette Girl Outside In Yellow Flowers

Flowering plants are heterosporous, producing two types of spores. Microspores are produced by meiosis inside anthers while megaspores are produced inside ovules, inside an ovary. In fact, anthers typically consist of four microsporangia and an ovule is an integumented megasporangium. Both types of spores develop into gametophytes inside sporangia. As with all heterosporous plants, the gametophytes also develop inside the spores (are endosporic).
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.