The world's oldest flower plant came from the water
A fossil of Moncechia, which appeared about 130 million years ago, became the oldest known flowering plant. 
Scientists have always believed that the first flowering plant in history would be a land plant. The University of Indiana says that although some of the angiosperms (the scientific name of flowering plants) occur in the water today, most of them live on land, and it is widely believed that these types of plants will evolve on land before they are returned to the water. Ancient botanist David Dilcher.
A paper published in the Proceedings of the National Academy of Sciences on August 17 identified the oldest flowering plant discovered to date, a water species in modern Spanish sediments.
Dilcher and colleagues from France, Germany and Spain have shown that fossils of a plant called Montsechia vidalii appeared on the scene between 130 million and 124 million years ago. It is assumed that terrestrial angiosperms have emerged at the time, although the current findings are earlier than any known land specimen. Montsechia also preceded the oldest known angiosperm Archaefructus, which occurred 124.5 million years ago.
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Flowers are all about sex," Dilcher said. The great advancement of angiosperms is the act of jointly selecting animals, allowing them to bring pollen to other individuals of their species (wind, of course, can do this too). This produces more diverse offspring than self-fertilization, regeneration or asexual spore production, for example, how ferns multiply. However, it can be said that another way to spread seeds is to use water flow, as Montsechia did. And "just at the beginning of [Angiosperm evolution], this is another way flowering plants use for gene exchange," Dilcher said.
The modern descendants of Montsechia, known as Ceratophyllum, look very similar to their ancient descendants and are found in the lakes of every continent. The existing six species release a sac containing pollen, called anther, which floats on the surface and then ruptures to release pollen grains. Then carry them through the tide, and if all goes well, fertilize them in other genus. According to the study, these plants lack roots and petals and contain simple seeds of a single seed.
"We don't know, it's hard to say, this is the world's first flower," Dilcher said. (Although it is the oldest discovered to date.) He added that these underwater plants almost certainly played a huge, under-recognized role in the early and subsequent evolution of angiosperms.
The study helped "uncover the global evolutionary and ecological events that accompany the rise of flowering plants," Donald Les, a plant evolution expert at the University of Connecticut, wrote in a commentary in the same journal that he did not participate in the study.
