History of flowers

Flowering plants, or angiosperms, are believed to have evolved from a now-extinct group of plants called gymnosperms. (Gymnosperms are naked-seed plants, and include conifers.) Flowering plants appear suddenly in the fossil record, around 100 million years ago, about the time dinosaurs were falling prey to a comet, or bad hygiene or whatever wiped ‘em out. Numerous genera seem to have suddenly appeared at the same time, some of which were very similar to our modern species.
It is generally believed angiosperms originated on the less fertile hills and uplands of tropical areas as the lower, more fertile areas had ferns, gymnosperms and other types of plants elbowing each other aside for space to thrive. Over time the flowering plants spread into the lowlands, where they became the dominant plants.
About 250,000 different species of angiosperms are known today. They include not only plants with our beloved conspicuous wildflowers, but trees such oak, willow, elm, and maple, all fruits and vegetables, nuts, herbs, cacti, coconut, corn, wheat, rice and other grains and grasses. And they have two, interrelated structures that separate them from all other plants: the flower and the fruit.
Flowers evolved as a device by which plants trick insects into transporting their pollen to other flowers (and possibly saving them having to evolve legs, a fashion sense, and dating).
The most primitive flowers likely resembled hepatica, a lovely spring wildflower. It has numerous floral parts, each distinctly separate from the others. By comparing these with a daisy or an orchid, it is possible to observe the four primary trends in flower evolution.
These trends are:
1) A reduction in floral parts. - Many specialized flowers have fewer stamens and carpels (or pistils), and always in a definite number.
2) Fusion of floral parts - Petals and carpels, in particular, have become fused, sometimes in elaborate fashion.
3) Elevation of floral parts above the ovary - In primitive flowers, the floral parts rise from the base of the ovary. These ovaries are referred to as superior. In more advanced flowers the floral parts are above the ovary. These ovaries are referred to as inferior.
4) Changes in symmetry - The radial symmetry of primitive flowers has given way to bilateral symmetry.

Just as all evolution is the consequence of chance and selection and reaction to the weirdest stuff, wind-driven pollination gave way to, probably, beetles feeding on plants that secreted droplets of sticky sap that contained pollen grains. As the beetles developed a taste for the sappy plants, they inadvertently carried pollen from one plant to another. In some cases, this form of pollination was more efficient than wind-driven pollination, and voila, evolution is at the wheel and fence posts are a blur.
Flower evolution got a boost about 65 million years ago when the first butterflies, moths, bees and wasps appeared. As many of these long-tongued insects depend entirely upon flowers as their sole food source, flowers and insects alike had a profound effect on the other’s evolution. The relationship is advantageous to both: pollen is less likely to be wasted by insects that don’t have wanderlust for another nectar source, and these same insects have a private stash as their food source is inaccessible to competing insects. These flowers have evolved colors and odors that allow sensory recognition by pollinators and some, such as orchids and snapdragons, have evolved landing platforms and deep nectaries - nectar-secreting organs - which allow only specific insects to belly up to the bar.
In a nutshell - the husk of an angiosperm - that’s a bit of where our wildflowers came from