Some plants reproduce to form similar identical plants by sending out runners e.g. strawberry . This is termed asexual reproduction as it does not require reproduction by flowering. This type of reproduction is simple copying, but may not help a plant survive in the long-term particularly if there is sudden climate change as all plants are identical. You should contrast this to sexual reproduction in plants, which requires the formation of flowers so that genetic material is exchanged. This exchange creates variety in a new generation and aids survival of the plant species.
Flowers are a plant's reproductive organs.
The male gametes are pollen. The female gametes are ovules. Flowers enable pollen from one plant can fertilise ovules of another plant. This is called cross-fertilisation and helps create a greater variety in the plants. Variety aids survival as usually some plants will adapt and live in any new conditions.