The fifth programme explores the alliances formed between the animal and plant worlds. Attenborough dives into Australia's Great Barrier Reef and contrasts the nocturnal feeding of coral, on microscopic creatures, with its daytime diet of algae. Some acacias are protected by ants, which will defend their refuge from any predator. Besides accommodation, the guards are rewarded with nectar and, from certain species, protein for their larvae as well. Fungi feed on plants but can also provide essential nutriment to saplings (Mycorrhiza). The connection is never broken throughout a tree's life and a quarter of the sugars and starches produced in its leaves is channelled back to its fungal partners. Meanwhile, fungi that feed on dead wood leave a hollow trunk, which also benefits the tree. Orchids enjoy a similar affiliation. Lichens are the product of a relationship between fungi and a photosynthetic associate, usually algae. They are extremely slow-growing, and a graveyard is the perfect location to discover their exact longevity. Mistletoe is a hemiparasite that obtains its moisture from a host tree, while using own leaves to manufacture food. Its seeds are deposited on another by the mistletoe tyrannulet, following digestion of the fruit. The dodder (Cuscuta) is also parasitic, generally favouring nettles, and siphons its nourishment through periodic 'plugs' along its stem. The rafflesia has no stem or leaves and only emerges from its host in order to bloom — and it produces the largest single flower: one metre across.

Bladderwort utricularia is a pond-dweller that is among the fastest known, its traps snapping shut in less than a millisecond. As the seasons change, David demonstrates how plants operate on a different time scale to us; how they modify their lives according to the time of year. We discover insects’ hidden links with plants, both as pests and pollinators. UV-sensitive 3D cameras reveal the invisible alter-ego of plants and their flowers’ mesmerizing patterns; a parallel-dimension of strange colours and stunning patterns through which plants communicate with them. With the aid of visual effects, David steps among the swirling vortices of plant scent; communication signals with which plants are inextricably plugged in to the natural world. And using a tuning fork, he demonstrates how plants and insects can even communicate with music. As autumn envelopes the Gardens, fungi reveal themselves not as the enemies of plants but their vital allies. In Kew’s atmospheric Fungarium, David discovers a specimen that has the power of mind control and another that lives underground where it has grown to be so big it can be counted as the largest single organism on the planet. It is 6 times bigger than Kew Gardens itself.

Witness the secret powers of extraordinary animals, experience the world as they do and see the SUPER/NATURAL side of nature as never before. Executive produced by James Cameron and narrated by Benedict Cumberbatch, this series uses the scientific innovations and leading-edge filmmaking technology to reveal the secret powers and super-senses of the world’s extraordinary animals. See flowers in bee-vision to eavesdropping on conversations between elephant seals to soaring the length of a football field with glow-in-the-dark squirrels.
They say in nature that only the strongest survive. But when cooperation and communication bring animals and plants together and superpowers combine even the most vulnerable can become unstoppable. If you think you know nature, think again.

The third episode is devoted to the ways in which plants reproduce. Pollen and a stigma are the two components needed for fertilisation. Most plants carry both these within their flowers and rely on animals to transport the pollen from one to the stigma of another. To do this, they attract their couriers with colour, scent and nectar. It isn't just birds that help pollination: some mammals and reptiles also do so. However, it is mostly insects that are recruited to carry out the task. To ensure that pollen is not wasted by being delivered to the wrong flower, some species of plant have developed exclusive relationships with their visitors, and the gentian and its attendant carpenter bees is one example. Since pollen can be expensive to produce in terms of calories, some plants, such as orchids, ration it by means of pollinia and a strategically placed landing platform. Other orchids offer no reward for pollination, but instead mislead their guests by mimicking their markings and aroma, thus enticing males to 'mate' with them (Pseudocopulation). The most extreme fertilisation method is one of imprisonment, and one plant that uses it is the dead horse arum. It is often found near gull colonies, and mimics the appearance and smell of rotting flesh. Blow-flies are attracted to it, and are forced to stay the night before being allowed to depart in the morning, laden with pollen. Finally, Attenborough introduces the world's largest inflorescence: that of the titan arum.

Professor of physics Jim Al-Khalili investigates the most accurate and yet perplexing scientific theory ever - quantum physics, the perplexing theory of sub-atomic particles. Turning his attention to the world of nature, can quantum mechanics explain the greatest mysteries in biology? The European robin navigates using one of the most bizarre effects in physics - quantum entanglement, a process which seems to defy common sense. Jim finds that even the most personal of human experiences - our sense of smell - is touched by ethereal quantum vibrations. According to new experiments it seems that our quantum noses are listening to smells. Jim discovers that the most famous law of quantum physics - the uncertainty principle - is obeyed by plants and trees as they capture sunlight during the vital process of photosynthesis. Jim wonders if the strange laws of the sub-atomic world, which allow objects to tunnel through impassable barriers in defiance of common sense, could effect the mechanism by which living species evolve?

The next instalment focuses on dietary needs and how different species have evolved beaks to suit their individual requirements. The latter come in a multitude of forms. Blue tits and goldfinches have beaks akin to tweezers, with which to extract seeds, while the hawfinch's razor-like bill can deal with a cherry-stone. However, the crossbill is the only finch that can twist its mandibles in opposite directions. Jays store acorns for winter by burying them in the ground, whereas woodpeckers can keep up to 60,000 of them in one tree trunk. Sap is also desirable, and there are a variety of methods used to obtain it. The hoatzin is the only specialised leaf-eater, and accordingly has a digestive system more akin to that of cattle. Plants recruit birds to aid pollination, and offer nectar as a reward. Hummingbirds eat little else, and the sword-bill's beak is the longest of any bird in relation to its body. Insects are also highly prized, and Galapagos finches are shown to possess some ingenuity as they not only strip bark, but also use 'tools' to reach their prey. Crows are hailed as being among the most intelligent birds, and one is shown using a twig to spear a grub within a fallen log. The robin is an opportunist, and Sir Attenborough observes one seizing morsels as he digs a patch of earth. In South America, a cattle tyrant sits atop an obliging capybara and uses its vantage point to spot passing food that may be dislodged by its grazing partner.