The first episode looks at the rose. The rose has always meant so much to Britain - it is embedded in our history, our fairy tales and our hearts. Carol goes on a very British plant odyssey. To understand the origins of our most cherished garden flower, we need look no further than the hedgerow. Our native dog rose - Rosa canina - has changed very little in 37 million years. Its prickles, acting like tiny crampons, allow it to climb above other plants and protect them from being eaten.

There are 6000 delightful varieties of tulips in the world today, with new colours and forms being cultivated every year. Carol Klein's odyssey to uncover the colourful history of this popular flower begins high in the mountains of Eastern Turkey where a species tulip, one of the early ancestors of those we grow in our gardens, can be found flourishing in the harshest of environments; a feat only possible due to its extraordinary evolution. Thermal imaging cameras reveal a small pocket of warm air trapped inside the flower's petals giving visiting pollinators a cosy place to rest their flight muscles. Back at sea level, Carol visits Istanbul's Rustem Pasha Mosque, richly decorated with painted tulips on every surface, and discovers how in the 15th and 16th centuries, Ottoman sultans, excited by the bright and variable colours of tulips, worked out how to cross-breed them to create ever more extravagant flowers.

Carol examines the intricate biology of the iris and looks into its intimate relationship with bees, using an endoscopic camera to reveal how the insect uses ultraviolet vision to see each flower. She also explores its cultural significance to mankind over thousands of years, learning of the importance of some species in the funeral traditions of Islam and its use in perfume manufacture in Florence. Plus, Carol meets an enthusiast rebuilding the iris collection of artist Cedric Morris

Carol takes a look at history and development of the water lily, a plant of unlikely economic importance, spiritual significance and artistic inspiration. She meets a leading experts in water-lily breeding to find out about a plant-insect relationship that brings about a dramatic overnight colour and sex change, and learns about its unique prehistoric pollinating system. She also visits South Korea and takes part in a festival held in honour of the lotus, a close relative of the water lily that is revered by Buddhist monks.