Universal in objective – sexual reproduction for a rooted, stationary land plant!
88% of all known plant species are flowering plants (260,000)
Flowers: A Marvelous Innovation Flowering plants first appeared around 140 million years ago (Upper Jurassic). At that time the dominant forms of plant life were gymnosperms, cycads (at left) , and ferns. Oldest flower fossil is 125 million years old. Slide text from: http://herbarium.usu.edu/Teaching/bio2410/FLOWERS.ppt
Flowers dominate (except…)
Success of the flower as a repro. strategy makes it the dominant plant of the warmer lats
In far north or high altitudes, we see gymnosperms (like fir, spruce) remain
Butterflies – vision & color http://webexhibits.org/causesofcolor/17C.html
Butterflies are great learners
Butterflies, whose color vision detects more wavelengths than either humans' or bees', can also associate colors with rewards. In one of the more dramatic experiments, cabbage butterflies learned a color with beelike speed -- after just one experience with a reward. Given a choice of two colors, the butterflies picked the rewarding hue 82 percent of the time, reported Alcinda C. Lewis of Boulder, Colo., and a colleague in Insect-Plant Interactions (CRC Press, Boca Raton, Fla., 1990). Pipevine swallowtails learned a preference for yellow or magenta within 10 visits to treat-laden flowers, reported Weiss in the May 1997 Animal Behaviour.
The butterflies could also keep two learned colors in mind for different purposes, Weiss says. She and Daniel R. Papaj of the University of Arizona have trained female pipevines to associate one color with sources of nectar and another with suitable spots for laying eggs.
In a famous example, Darwin described an orchid from Madagascar that had a foot-deep nectar well that kept the sweet liquid far out of reach of all known butterflies and moths. But the existence of the flower led him to predict the existence of a specialized moth with a foot-long proboscis that, like a straw, could reach the deep reward. Indeed, after Darwin’s death, researchers discovered just such an insect, and named it the “Predicta moth” in honor of Darwin’s educated guess.
Isabel Friedman, Apis mellifera on Asteraceae, Morris Arboretum October 13, 2007
Bees are important pollinators
Bees’ bodies well adapted to receive, transfer pollen
Bees’ vision includes UV spectral regions, but bees do not distinguish red as a visible color
Red-colored flowers are often bird-pollinated and not adapted for bees
(poinsettia, hibiscus, red-flowered sages)
Colony Collapse Disorder?
Researchers are concerned that trucking colonies around the country to pollinate crops, where they intermingle with other bees from all over, helps spread viruses and mites among colonies. Additionally, such continuous movement and re-settlement is considered by some a strain and disruption for the entire hive, possibly rendering it less resistant to all sorts of systemic disorder.  One major US beekeeper reports moving his hives from Idaho to California in January, then to apple orchards in Washington in March, to North Dakota two months later, and then back to Idaho by November - a journey of several thousands of miles. Others move from Florida to New Hampshire or to Texas; nearly all visit California for the almond bloom in January. Keepers in Europe and Asia are generally far less mobile, with bee populations moving and mingling within a smaller geographic extent (although some keepers do move longer distances, it is much less common). This wider spread and intermingling in the US has resulted in far greater losses from Varroa mite infections in recent years. 
Bougainvillea (Nyctaginaceae) Bracts !
Poinsettia (Euphorbiaceae) Bracts !
Hummingbird, sunbird, and honeycreeper – nectar feeding bird pollinators
Pollen nucleus journey may be long! http:// agbiosafety.unl.edu/education/lessons/breeding_lesson.htm Long corolla flowers like Chalice vine (Solandra) or trip from top silks of ear of corn to bottom kernels….
Pollen tube ultimately comprises 3 male nuclei
Tube nucleus is responsible for growth of pollen tube
Generative cell divides into two (2) (!) sperm nuclei by arrival at ovule entry (micropyle)
Following the division of the pollen’s sperm nucleus into two identical haploid nuclei, there are two separate fertilization events