The shoots that come from the seeds, like all shoots, can sense the light – they can see. [David Attenborough, The Private Life of Plants]
This episode – Growing - focuses on the diverse ways plant grow to catch the sun – an essential requirement with water, air and few minerals. With different mechanisms to defend their leaves such as ferocious spines, painful stings, poisonous saps and near perfect disguise have been developed.
Mimosa pudica with leaves open and closed
The ability to move fast and deter predators such as the Mimosa with a dramatic and radical solution where upon touch, it instantaneously folds its leaves and an additional tap makes the leaves with stem flop to the ground. More drastically, the Venus flytrap which traps insects when triggered and the insects’ further struggles only helps to stimulate the plant to close its leaves more. In impoverished waterlogged soil, the Trumpet pitchers supplement themselves with bodies of their predators as they fall down their tubular leaves. An advertisement of sweet nectar lures the plants prey, the slippery sides makes for accidental slip through which makes for a soup of dissolved insect corpses. The largest pitcher of all, Nepenthes rajah, which can only be found on Mount Kinabalu, has a fluid capacity of three pints and also preys on small rodents.
The Venus flytrap , the Nepenthes rajah and the Sarracenia
By either catching insects (and small rodents) or absorbing gases and harnessing the energy of the sun, leaves manufacture food for the plant.