Plants are amazing organism and are ultimately responsible for all major life forms on the planet. Without plants, there would be little breathable oxygen and no food for animal life. Even the creatures that live in the depths of the ocean where no plants grow still rely on the phytoplankton that lives and dies above to filter down and feed it. Many plants reproduce by flowering. This gives rise to the question of what is the life cycle of a flowering plant?
It sounds like a simple question and easily answered. The seed germinates, produces a plant which grows for a set time and then it flowers. The flower gets pollinated and then produces seeds and fruit. End of cycle. This is true for a lot of plants, but not all.
Take the Agave, also known as a Century Plant. It grows outdoors in the tropics, for decades (in some cases over 100 years) and then, when the weather conditions are just right it send up a flower stalk, some are over 30 feet tall. The flowers at the end of the stalk often smell bad and are attracting bats, which act as Pollinators. Now though, instead of producing seeds or fruits the Agave produced bulbs and living plants. The plant dies, the stalk falls in the wind and rain literally throwing out little plant into the mud. Then the cycle starts again!
Then you have trees that can flower, produce seeds and keep going with the same cycle every year based upon light. Though some trees aren’t based on yearly light cycles but upon weather patterns. The Mango tree produces millions of flowers and if the weather is dry they get pollinated, if it rains too much they don’t. After pollination they need rain to bear.
Then there are plants that constantly produce flowers, but rarely bear seeds. Their life cycle is dependent upon insect or birds to act as the pollinators. If those creatures are not available, you get flowers but the cycle never gets completed. These include domestic orchids, Plumeria, and Alamandas. How do they reproduce? Often from cuttings!
The simple answer to what is the life cycle of a flowering plant is the seed germinates and grows. Once conditions are right the plant uses its stored energy to produce the flower. The flower gets pollinated through various means and produces seeds. Then the cycle starts again. But there is a lot of variety for such a simple cycle.