Short answers, pulled from the story.
A flower is the reproductive structure of a flowering plant, also known as a blossom or bloom. It is typically built from four whorls arranged around the tip of a stalk: the calyx of sepals, the petals, the male stamens, and the female gynoecium.
Flowers first evolved between 150 and 190 million years ago, during the Jurassic. The earliest definitive fossil evidence comes from between 125 and 130 million years ago, during the Early Cretaceous.
Pollination is the movement of pollen from a flower's male parts to its female parts, either within the same plant in self-pollination or between plants in cross-pollination. Around 80% of flowering plants use living vectors such as insects, birds, and bats, while the rest rely on wind or, much less commonly, water.
The ABC model describes how three groups of genes control flower development. A genes alone produce sepals, A and B together produce petals, B and C together produce stamens, and C genes alone produce carpels.
Flowers range in size from 0.1 mm in duckweed to 1 m in diameter in the corpse flower. This spans flowers that are highly reduced and understated to ones that dominate the structure of the plant.
Humans use flowers for decoration, medicine, drugs, food, spices, perfumes, and essential oils. Around half of all cropland grows three flowering plants, rice, wheat, and corn, and flowers also carry cultural meaning in burial, love, celebration, art, flags, and emblems.
Double fertilisation is a process unique to flowering plants in which a pollen tube releases two sperm cells. One sperm fuses with an egg to form a diploid zygote, while the second fuses with the two polar nuclei of the central cell to form a triploid nutrient tissue.