1 00:00:09,200 --> 00:00:12,999 I'm exploring the fascinating world of plants, 2 00:00:13,132 --> 00:00:16,514 from the most bizarre to the most beautiful. 3 00:00:21,102 --> 00:00:24,452 With new techniques and in 3D, 4 00:00:24,569 --> 00:00:27,521 we can unravel their deepest secrets. 5 00:00:33,321 --> 00:00:37,987 We can move from our time scale to theirs. 6 00:00:42,653 --> 00:00:45,841 We can see how they struggle with one another, 7 00:00:48,890 --> 00:00:52,006 how they get help from some animals 8 00:00:53,056 --> 00:00:55,471 but have the battle with others, 9 00:00:56,038 --> 00:00:58,793 and survive against the odds. 10 00:01:00,260 --> 00:01:03,124 And we can watch all these dramas taking place 11 00:01:03,125 --> 00:01:05,675 in a way that is impossible in the wild 12 00:01:05,708 --> 00:01:08,824 in one unique institution. 13 00:01:10,174 --> 00:01:13,279 the Royal Botanic Gardens at Kew. 14 00:01:15,111 --> 00:01:16,995 In this living laboratory, 15 00:01:17,061 --> 00:01:21,559 we can discover plants' most extreme adaptations for survival 16 00:01:25,309 --> 00:01:28,563 and we can glimpse Kew's tiny weapons 17 00:01:28,564 --> 00:01:32,247 in the battle to protect the future of all plants - 18 00:01:32,347 --> 00:01:33,663 seeds. 19 00:01:37,677 --> 00:01:45,865 Kingdom of Plants with David Attenborough 20 00:01:55,935 --> 00:02:00,784 Ever since plants first moved out of water and colonized the land, 21 00:02:00,967 --> 00:02:04,550 they've advanced into drier and drier places 22 00:02:04,782 --> 00:02:07,682 and evolved specially set-up adaptations 23 00:02:07,854 --> 00:02:09,736 in order that they can do so. 24 00:02:10,270 --> 00:02:14,902 Today, deserts cover about a third of the land's surface of the earth 25 00:02:14,986 --> 00:02:16,685 and they are spreading rapidly. 26 00:02:17,002 --> 00:02:21,939 But some plants have developed some truly extraordinary strategies 27 00:02:22,022 --> 00:02:26,389 to enable them to survive in the driest of places. 28 00:02:41,840 --> 00:02:48,139 Survival 29 00:02:49,661 --> 00:02:52,742 In deserts where water is scarce, 30 00:02:52,776 --> 00:02:56,756 one major strategy is to remain passive during the day 31 00:02:56,789 --> 00:02:58,429 when temperatures soar 32 00:02:58,478 --> 00:03:01,657 and only become active in the cool of the night. 33 00:03:06,738 --> 00:03:10,966 This desert in Kew's Princess of Wales Conservatory 34 00:03:11,016 --> 00:03:15,589 contains plants from every regions all around the world. 35 00:03:21,605 --> 00:03:23,162 And in mid-summer, 36 00:03:23,423 --> 00:03:27,685 one plant here does something truly astonishing. 37 00:03:30,636 --> 00:03:36,405 Don't be deceived by the shrivel untidy appearance of this cactus. 38 00:03:36,701 --> 00:03:41,634 This, in fact, one of the most remarkable members of the cactus family, 39 00:03:41,862 --> 00:03:44,273 is called Hylocereus - 40 00:03:44,306 --> 00:03:46,503 "the Queen of the Night". 41 00:03:46,814 --> 00:03:48,731 It lives in Mexico 42 00:03:48,879 --> 00:03:51,108 where, during the summer midday, 43 00:03:51,370 --> 00:03:56,418 the temperatures can reach a crippling 50 degrees centigrade. 44 00:03:56,779 --> 00:03:59,992 So during the day, it doesn't do much. 45 00:04:00,761 --> 00:04:02,221 But once a year, 46 00:04:02,417 --> 00:04:03,892 for one night only, 47 00:04:04,040 --> 00:04:07,154 it becomes a thing of astounding beauty. 48 00:04:36,067 --> 00:04:39,574 The flowers usually open on a night of the full moon. 49 00:04:39,935 --> 00:04:42,689 And as they do so, they give off a smell 50 00:04:42,722 --> 00:04:46,803 which attracts night flying animals, large and small. 51 00:04:47,606 --> 00:04:48,882 And as they get nearer, 52 00:04:48,899 --> 00:04:51,294 they can see the great white flowers, 53 00:04:51,408 --> 00:04:53,687 bright in the light of full moon. 54 00:04:53,720 --> 00:04:56,374 And they go to them to sip the nectar 55 00:04:56,522 --> 00:04:59,505 and, in doing so, pollinate the cactus. 56 00:05:02,128 --> 00:05:05,167 It might seem strange, even risky 57 00:05:05,283 --> 00:05:09,898 for the plant to restrict its flowering to just one night of the year. 58 00:05:11,965 --> 00:05:15,947 But this strategy works for Hylocereus. 59 00:05:16,964 --> 00:05:21,035 Its flowers are the biggest and brightest around 60 00:05:21,668 --> 00:05:25,517 and they offer its pollinators a nectar banazar - 61 00:05:30,083 --> 00:05:31,033 bats. 62 00:05:34,770 --> 00:05:37,887 With the aid of technology, we can imagine them, 63 00:05:37,954 --> 00:05:40,868 thousands of miles from their natural habitat, 64 00:05:41,102 --> 00:05:43,252 here in Kew. 65 00:05:51,672 --> 00:05:55,372 Bats pollinate all kinds of cacti. 66 00:06:05,124 --> 00:06:08,174 In spring time in Southern American deserts, 67 00:06:08,191 --> 00:06:12,889 there is always a cactus of one kind or another in bloom. 68 00:06:30,912 --> 00:06:35,811 A multitude of species compete for the attentions of nocturnal pollinators 69 00:06:35,878 --> 00:06:39,661 using bright pedals and powerful scent. 70 00:06:43,864 --> 00:06:47,480 The sweetest perfumes attract insects. 71 00:06:52,113 --> 00:06:54,900 But flowers that are pollinated by bats 72 00:06:54,968 --> 00:06:57,101 are rather more pungent. 73 00:07:00,099 --> 00:07:03,682 They give off the stench of rotting fruit. 74 00:07:11,386 --> 00:07:13,184 To nectar feeding bats, 75 00:07:13,251 --> 00:07:16,085 that smell is irresistible. 76 00:07:18,434 --> 00:07:21,033 They fly from cactus to cactus, 77 00:07:21,184 --> 00:07:23,100 sipping out the nectar. 78 00:07:28,055 --> 00:07:32,356 Each bat can consume more one and a half times its bodyweight of nectar. 79 00:07:32,453 --> 00:07:34,086 in a single night. 80 00:07:41,090 --> 00:07:43,406 Very tall columnar species, 81 00:07:43,439 --> 00:07:46,505 produce flowers right to the very top of their stems 82 00:07:46,522 --> 00:07:49,242 where they are easily smelt and seen, 83 00:07:49,359 --> 00:07:51,376 and easily reached. 84 00:07:54,808 --> 00:07:57,925 Some provide additional facilities. 85 00:07:59,441 --> 00:08:02,323 Espostoa guentheri from Bolivia 86 00:08:02,573 --> 00:08:05,211 sprouts a landing strip beneath its flowers, 87 00:08:05,212 --> 00:08:08,111 a pat of fur on which the bats can alight 88 00:08:08,127 --> 00:08:11,094 without damaging their wings on the spines. 89 00:08:13,860 --> 00:08:16,697 But in Mexico, bats and cacti 90 00:08:16,781 --> 00:08:20,413 have a even more extraordinary relationship. 91 00:08:21,546 --> 00:08:25,679 Each year, bats migrate across 1,000 miles of desert 92 00:08:25,712 --> 00:08:28,945 from central Mexico to Arizona. 93 00:08:31,665 --> 00:08:34,749 Pregnant females, 100,000 of them, 94 00:08:34,782 --> 00:08:38,481 are on their way to special maternity caves in the north 95 00:08:38,531 --> 00:08:40,948 where they will give birth to their young. 96 00:08:42,398 --> 00:08:46,534 The bats get all the nectar they need to sustain their journey 97 00:08:46,618 --> 00:08:50,350 and in return, they pollinate the cacti. 98 00:08:52,417 --> 00:08:57,154 This annual bat migration coincide exactly 99 00:08:57,238 --> 00:09:00,553 with the blooming of the night flowering cacti, 100 00:09:01,087 --> 00:09:05,619 so the bats can fly along a nectar corridor, 101 00:09:10,657 --> 00:09:13,573 and so can cross a patch of desert 102 00:09:13,673 --> 00:09:16,082 that, otherwise and at other times, 103 00:09:16,217 --> 00:09:17,938 would be impossible for them. 104 00:09:26,020 --> 00:09:28,575 By the time the bats return with their pups, 105 00:09:28,708 --> 00:09:32,557 the cacti are able once again to provide the bats with food, 106 00:09:32,774 --> 00:09:34,939 this time, their fruits. 107 00:09:35,739 --> 00:09:38,573 The bats carry with them in their stomach the fruit 108 00:09:38,706 --> 00:09:40,622 and the seed it contains. 109 00:09:40,810 --> 00:09:41,976 And in due course, 110 00:09:41,977 --> 00:09:45,725 they deposit those seeds with a nice little package of fertilizer 111 00:09:45,793 --> 00:09:47,658 farther down the corridor. 112 00:09:48,092 --> 00:09:50,892 So the corridors are self perpetuating. 113 00:09:51,358 --> 00:09:55,379 The bats, in effect, are cactus farmers. 114 00:10:28,782 --> 00:10:30,727 Perhaps the most extraordinary thing 115 00:10:30,742 --> 00:10:32,981 about these night blooming cacti 116 00:10:33,048 --> 00:10:36,635 is that, just a few hours after the flowers burst open, 117 00:10:36,785 --> 00:10:38,669 they begin to close. 118 00:10:47,033 --> 00:10:48,966 By the time the sun appears, 119 00:10:49,071 --> 00:10:51,838 they have already wilted and died. 120 00:10:55,987 --> 00:11:00,069 This is all part of their survival strategy. 121 00:11:02,608 --> 00:11:05,922 The closed pedals form a protective shield 122 00:11:06,006 --> 00:11:08,406 around the newly pollinated seeds 123 00:11:08,622 --> 00:11:11,222 locking vital moisture inside. 124 00:11:25,874 --> 00:11:27,690 The light of a new day 125 00:11:27,829 --> 00:11:32,578 reveals the bizarre nature of dry zone plants. 126 00:11:40,509 --> 00:11:44,458 These are surely some of the oddest looking species there are. 127 00:11:45,080 --> 00:11:46,959 And their strange shapes 128 00:11:47,180 --> 00:11:50,978 are a direct response to the harsh conditions. 129 00:11:55,644 --> 00:12:00,349 These plants will stay in the baking sun to collect the light they need, 130 00:12:01,682 --> 00:12:04,148 but they must also retain their moisture. 131 00:12:07,813 --> 00:12:11,584 Many do that by turning either their green stems 132 00:12:11,635 --> 00:12:15,334 or their waxy leaves into reservoirs. 133 00:12:19,616 --> 00:12:22,262 This extraordinary cactus from Mexico 134 00:12:22,279 --> 00:12:24,919 is covered in thick white hair. 135 00:12:25,503 --> 00:12:27,934 It's called "the old man". 136 00:12:29,903 --> 00:12:33,219 This fur not only provides shade, 137 00:12:33,269 --> 00:12:37,273 but restricts the circulation of the air around the surface of the stem 138 00:12:37,284 --> 00:12:39,972 and that reduces water loss. 139 00:12:43,342 --> 00:12:45,871 In even hotter and drier climates, 140 00:12:45,988 --> 00:12:49,104 some plants avoid the sun all together. 141 00:12:50,853 --> 00:12:52,786 This is Fenestraria - 142 00:12:52,851 --> 00:12:55,091 the window plant. 143 00:12:56,357 --> 00:12:58,689 It grows in the Kalahari Desert 144 00:12:58,723 --> 00:13:01,907 with most of its body buried beneath the soil. 145 00:13:04,122 --> 00:13:08,127 Only the blunt flat tips of its leaves are exposed. 146 00:13:11,976 --> 00:13:14,592 Each contains tiny lenses 147 00:13:14,642 --> 00:13:18,013 which transmit the sunlight down through the vertical leaf 148 00:13:18,097 --> 00:13:21,925 on to its green photosynthesizing cells. 149 00:13:28,010 --> 00:13:32,494 Some desert plants that live in exceptionally hot dry conditions 150 00:13:32,682 --> 00:13:35,765 take even more drastic measures. 151 00:13:37,300 --> 00:13:41,839 Leaves are very thin and have a large surface area 152 00:13:42,035 --> 00:13:44,626 so they lose a lot of moisture in heat. 153 00:13:44,724 --> 00:13:48,379 And many desert plants have done without them all together. 154 00:13:48,691 --> 00:13:53,361 Instead the valuable green pigment develops in the stems. 155 00:13:53,787 --> 00:13:57,394 And desert stems are often very thick and swollen 156 00:13:57,476 --> 00:14:00,294 and that enables a plant to store water in them. 157 00:14:00,590 --> 00:14:01,557 Not only that, 158 00:14:01,885 --> 00:14:06,130 but some desert plants have pleats in these stems 159 00:14:06,474 --> 00:14:08,703 so that when there is sudden rainstorm, 160 00:14:08,801 --> 00:14:12,325 those ridges can suck up all the moisture while it is there 161 00:14:12,407 --> 00:14:15,081 and expand in order to hold it. 162 00:14:16,734 --> 00:14:20,325 The stems of some of these species swell to such a degree 163 00:14:20,439 --> 00:14:23,258 that they become almost spherical. 164 00:14:27,257 --> 00:14:31,552 A sphere has the minimum surface area for any given volume 165 00:14:31,617 --> 00:14:35,469 and that enables the plant to hold as much water as possible. 166 00:14:37,797 --> 00:14:41,287 This one is Copiapoa from northern Chile 167 00:14:41,516 --> 00:14:44,058 where it never rains at all. 168 00:14:45,041 --> 00:14:47,745 But, in fact, it doesn't need it. 169 00:14:50,335 --> 00:14:53,221 Under a microscope, you can see why. 170 00:14:56,728 --> 00:14:59,727 There are thousands of tiny jagged structures 171 00:14:59,874 --> 00:15:02,186 on which the morning dew condenses 172 00:15:02,267 --> 00:15:04,825 so that the plant can collect it. 173 00:15:09,956 --> 00:15:13,511 But the ultimate is this plant. 174 00:15:14,282 --> 00:15:17,537 It's hidden between these light colored pebbles - 175 00:15:19,395 --> 00:15:22,100 Blossfeldia from Argentina. 176 00:15:25,346 --> 00:15:27,869 This is the only flowering plant 177 00:15:28,033 --> 00:15:31,475 that can withstand total desiccation 178 00:15:31,803 --> 00:15:33,393 for months on end. 179 00:15:33,590 --> 00:15:38,016 And then with a shower of rain or a little bit of water, 180 00:15:38,081 --> 00:15:42,079 it comes to life and produces a tiny little flower. 181 00:15:49,292 --> 00:15:52,128 This ability to wait for the right conditions 182 00:15:52,144 --> 00:15:55,537 is the trump card that enables many plants 183 00:15:55,586 --> 00:15:57,880 to survive in the dry zone. 184 00:16:01,256 --> 00:16:02,338 In many deserts, 185 00:16:02,453 --> 00:16:06,437 plants must endure months, sometimes, years, of drought. 186 00:16:11,878 --> 00:16:14,910 They do it by slowing down their metabolism 187 00:16:14,975 --> 00:16:17,828 and going into a state of virtual dormancy. 188 00:16:21,172 --> 00:16:23,680 But when rains finally arrive, 189 00:16:23,877 --> 00:16:27,825 plants like these suddenly come to life. 190 00:16:29,202 --> 00:16:32,760 Their dried out tissues absorb water like sponges. 191 00:16:35,251 --> 00:16:36,776 And once expanded, 192 00:16:36,923 --> 00:16:39,496 they use the moisture to grow. 193 00:16:52,609 --> 00:16:57,608 This primitive wakeless plant from the Chihuahuan Desert in Mexico 194 00:16:57,837 --> 00:17:01,591 is a spikemoss, Selaginella. 195 00:17:03,475 --> 00:17:06,589 It's also called "the resurrection plants" 196 00:17:06,737 --> 00:17:10,614 because its ability to seemingly come back from the dead. 197 00:17:11,359 --> 00:17:15,456 Rain starts a complex biochemical change in its cells 198 00:17:15,555 --> 00:17:18,293 that enables it to ramp up its metabolism 199 00:17:18,325 --> 00:17:20,916 and grow very quickly while it can. 200 00:17:26,079 --> 00:17:29,962 But the most spectacular consequence of rain in the desert 201 00:17:29,979 --> 00:17:33,110 is an explosion of color. 202 00:18:16,576 --> 00:18:20,675 Desert flowers are as colorful as any of the world. 203 00:18:20,904 --> 00:18:23,575 They have to attract pollinators quickly 204 00:18:23,625 --> 00:18:26,309 before the deserts dry out once again. 205 00:18:39,951 --> 00:18:44,540 But moisture in the soil could evaporate almost as quickly as it arrives 206 00:18:44,556 --> 00:18:47,604 and after a brief bloom, they die. 207 00:19:01,470 --> 00:19:05,602 Desert plants could only grow when the conditions are right 208 00:19:05,799 --> 00:19:09,716 and that maybe only for a few short periods in the year. 209 00:19:10,126 --> 00:19:11,977 So many desert plants 210 00:19:12,190 --> 00:19:14,879 take a long time to reach full size. 211 00:19:14,993 --> 00:19:19,746 That agave there, for example, is over 40 years old. 212 00:19:20,008 --> 00:19:21,499 But during that time, 213 00:19:21,566 --> 00:19:24,287 it has manufactured food and gathered water 214 00:19:24,335 --> 00:19:28,089 and stored them in its great fat leaves, 215 00:19:28,548 --> 00:19:30,221 but it's not yet adult. 216 00:19:30,827 --> 00:19:32,301 This one is. 217 00:19:33,219 --> 00:19:37,825 This agave has started to withdraw that water and food from it leaves. 218 00:19:37,858 --> 00:19:41,497 So now, they are beginning to crumple and wilt. 219 00:19:41,759 --> 00:19:43,447 And it uses that food 220 00:19:43,644 --> 00:19:47,791 to fuel the growth of this huge mast-like stem 221 00:19:47,905 --> 00:19:51,249 that grows from its center and will carry the flowers. 222 00:19:51,626 --> 00:19:56,084 And it reaches its full height at extraordinary speed. 223 00:20:01,788 --> 00:20:06,263 It can grow by a quarter of a meter everyday. 224 00:20:11,246 --> 00:20:13,065 It reaches such a height 225 00:20:13,099 --> 00:20:15,425 that here in Kew's glass house, 226 00:20:15,491 --> 00:20:19,293 panes have to be removed from the root to let it through. 227 00:20:22,620 --> 00:20:25,063 This infrequently flowering 228 00:20:25,080 --> 00:20:28,423 has given this species of agave a nick name - 229 00:20:28,718 --> 00:20:30,866 "the century plant". 230 00:20:34,011 --> 00:20:39,355 So why does the agave produce this huge tall mast? 231 00:20:39,634 --> 00:20:42,913 Well, some plants are pollinated by insects 232 00:20:43,109 --> 00:20:45,485 and you attract insects with smell. 233 00:20:45,764 --> 00:20:48,994 But this plant is pollinated by birds - 234 00:20:49,124 --> 00:20:50,091 humming birds. 235 00:20:50,288 --> 00:20:54,040 And birds have little or no sense of smell. 236 00:20:54,100 --> 00:20:58,237 To attract them, you have to exploit their very sharp sight. 237 00:20:58,433 --> 00:21:00,993 You have to produce flowers that are very bright 238 00:21:01,160 --> 00:21:05,703 and put them right at the top of a prominent tall mast. 239 00:21:11,121 --> 00:21:15,469 Growing at such a rate demands considerable effort. 240 00:21:20,175 --> 00:21:23,234 For the agave, it's terminal. 241 00:21:24,871 --> 00:21:27,536 The act of producing that mast 242 00:21:27,627 --> 00:21:30,627 is the last act in this plant's life. 243 00:21:30,733 --> 00:21:35,468 Having done it and been pollinated, it dies. 244 00:21:48,113 --> 00:21:51,566 Thanks to their extraordinary survival strategies, 245 00:21:51,687 --> 00:21:54,611 desert plants are able to thrive in places 246 00:21:54,626 --> 00:21:56,959 where others would die. 247 00:22:00,261 --> 00:22:05,573 But that makes them the focus of much unwanted attention. 248 00:22:08,451 --> 00:22:11,935 As a downside to success for a desert plant, 249 00:22:12,389 --> 00:22:14,950 the more water it stores, 250 00:22:15,126 --> 00:22:19,504 the more tempting it is for a thirsty animal to try and steal it. 251 00:22:20,035 --> 00:22:23,517 So desert plants have to have good defenses. 252 00:22:29,420 --> 00:22:31,784 The techniques they use can tell us something 253 00:22:31,814 --> 00:22:35,102 about the herbivores that try to feed on them. 254 00:22:37,555 --> 00:22:40,206 This Echinopsis from Argentina 255 00:22:40,221 --> 00:22:42,644 develops long strong spines 256 00:22:42,806 --> 00:22:46,473 as a defense against large grazing animals - 257 00:22:46,715 --> 00:22:47,669 llamas. 258 00:22:50,759 --> 00:22:53,984 But such defenses also provide hiding places 259 00:22:54,060 --> 00:22:58,222 where an insect or a spider can keep out of harm's way. 260 00:23:03,675 --> 00:23:06,871 There are other ways in which a plant can protect itself. 261 00:23:07,366 --> 00:23:09,168 You can disguise yourself, 262 00:23:09,198 --> 00:23:11,804 so you become virtually invisible 263 00:23:11,941 --> 00:23:14,378 as these stone plants have done. 264 00:23:14,379 --> 00:23:16,758 These are not pebbles as you might think. 265 00:23:16,788 --> 00:23:18,606 They are living plants. 266 00:23:23,029 --> 00:23:26,341 These are lithrobs from the deserts of Africa 267 00:23:26,371 --> 00:23:30,038 and their markings closely match their surroundings. 268 00:23:31,991 --> 00:23:33,986 What's more, they are varying color 269 00:23:34,062 --> 00:23:37,308 according to the rocks on which they grow. 270 00:23:37,470 --> 00:23:40,090 That's growing on pale rocks, 271 00:23:40,741 --> 00:23:43,271 and those on reddish rocks. 272 00:23:43,801 --> 00:23:48,528 Or you can load the water you contain 273 00:23:48,665 --> 00:23:51,512 with a particularly strong chemical 274 00:23:51,643 --> 00:23:54,309 which animals might find distasteful. 275 00:23:54,582 --> 00:23:57,747 This is the Peyote plant from Mexico. 276 00:23:58,081 --> 00:24:01,564 And its sap not only puts off animals, 277 00:24:01,595 --> 00:24:04,458 but has the property of suppressing pain, 278 00:24:04,680 --> 00:24:07,377 so the local people use it for that purpose 279 00:24:07,423 --> 00:24:10,177 and also in their religious rituals 280 00:24:10,269 --> 00:24:12,906 for it's also hallucinogenic. 281 00:24:20,125 --> 00:24:21,853 In colder regions, 282 00:24:21,944 --> 00:24:24,897 pine trees also have to conserve water 283 00:24:24,973 --> 00:24:26,139 for during the winter 284 00:24:26,153 --> 00:24:29,669 water in the soil is frozen and so beyond their reach. 285 00:24:30,290 --> 00:24:32,678 Little evaporate their leaves 286 00:24:32,705 --> 00:24:36,360 because they have been reduced to stiff tough needles. 287 00:24:39,162 --> 00:24:40,372 Like cacti, 288 00:24:40,464 --> 00:24:44,358 they also produce distasteful chemicals. 289 00:24:49,458 --> 00:24:53,457 The distinctive smell that you sense when you walk among pine trees 290 00:24:53,623 --> 00:24:55,955 come from volatile oils 291 00:24:56,001 --> 00:24:58,530 that the trees produce in their leaves. 292 00:24:59,174 --> 00:25:00,604 It's a form of defense. 293 00:25:01,035 --> 00:25:03,311 Most insects can't bear it, 294 00:25:03,588 --> 00:25:05,357 but one can - 295 00:25:05,388 --> 00:25:07,358 the pine aphid. 296 00:25:07,727 --> 00:25:09,526 When that attacks, however, 297 00:25:09,664 --> 00:25:12,909 the pine trees have a second line of defense. 298 00:25:14,693 --> 00:25:20,307 They produce that volatile oil from the cuts made by the insects 299 00:25:20,492 --> 00:25:22,044 in even greater quantity 300 00:25:22,045 --> 00:25:26,736 and that crucially changes the nature of the smells around the trees. 301 00:25:29,288 --> 00:25:34,410 Aphids infestation triggers a complex chain reaction from the pines. 302 00:25:35,610 --> 00:25:37,702 Each time an aphid bites, 303 00:25:37,733 --> 00:25:40,639 the pine releases oily vapor from the wound 304 00:25:40,685 --> 00:25:42,884 which fills the surrounding air. 305 00:25:45,991 --> 00:25:50,344 This triggers the release of further volatiles from other branches, 306 00:25:51,252 --> 00:25:53,528 even other trees. 307 00:25:58,495 --> 00:26:00,002 The effect multiplies 308 00:26:00,017 --> 00:26:05,262 until eventually whole forests become coat in pine scent. 309 00:26:14,705 --> 00:26:19,366 This scent cloud attracts predatory ladybirds. 310 00:26:19,797 --> 00:26:21,610 They are as sensitive to it 311 00:26:21,611 --> 00:26:24,087 as sharks are to blood. 312 00:26:39,683 --> 00:26:42,466 This is the eyed ladybird 313 00:26:42,528 --> 00:26:45,542 and it preys on pine aphids. 314 00:26:50,648 --> 00:26:52,832 It locates an infestation 315 00:26:52,833 --> 00:26:55,770 by following the trail of volatiles. 316 00:27:00,460 --> 00:27:01,830 And once there, 317 00:27:01,968 --> 00:27:05,136 it makes short work of the prey. 318 00:27:15,455 --> 00:27:18,348 It's a mutually beneficial arrangement. 319 00:27:18,808 --> 00:27:21,470 The ladybird gets an easy meal 320 00:27:24,023 --> 00:27:27,515 and the pine tree gets rid of a pest. 321 00:27:37,341 --> 00:27:39,695 Some dry zone plants use oils 322 00:27:39,772 --> 00:27:43,048 to defend themselves from other dangers, 323 00:27:43,325 --> 00:27:46,615 not from insects but other plants. 324 00:27:48,169 --> 00:27:50,507 This is a eucalyptus, 325 00:27:50,676 --> 00:27:53,384 famous for the oil in its leaves. 326 00:27:53,707 --> 00:27:56,398 It produces that oil in such quantity 327 00:27:56,551 --> 00:27:57,920 that, under certain conditions, 328 00:27:57,935 --> 00:28:01,304 it can form a blue haze above the tree. 329 00:28:01,856 --> 00:28:05,749 In fact, the Blue Mountains of New South Wales in Australia 330 00:28:05,841 --> 00:28:08,040 get their name from the haze 331 00:28:08,071 --> 00:28:11,102 that hangs over eucalyptus forests sometimes. 332 00:28:11,270 --> 00:28:14,576 When the leaves fall to the ground and rot, 333 00:28:14,638 --> 00:28:17,538 the oil leaches out into the soil. 334 00:28:17,698 --> 00:28:21,571 And then, reinforced by more oil secreted by the roots, 335 00:28:21,787 --> 00:28:24,254 it acts as an inhibitor 336 00:28:24,321 --> 00:28:29,392 that prevents other seeds of other plants from growing around its base, 337 00:28:29,558 --> 00:28:33,456 so reducing competition for the eucalyptus. 338 00:28:36,123 --> 00:28:39,927 Another species uses oils in a different way 339 00:28:43,227 --> 00:28:45,843 and a more dramatic one. 340 00:28:48,797 --> 00:28:53,341 If the temperature raises to 32 degrees centigrade, 341 00:28:53,546 --> 00:28:57,462 those substances in the leaves of this Cistus plant from the Mediterranean 342 00:28:57,579 --> 00:29:00,829 can spontaneously burst into flame. 343 00:29:25,574 --> 00:29:29,249 The flames reduce the Cistus to a cinder 344 00:29:30,882 --> 00:29:34,393 and the plant itself will never recover. 345 00:29:36,786 --> 00:29:40,485 But this is not a disastrous accident. 346 00:29:40,551 --> 00:29:43,951 The Cistus has evolved to burn. 347 00:29:46,135 --> 00:29:50,639 Such extraordinary sacrifice ensures a different kind of survival - 348 00:29:50,671 --> 00:29:52,804 survival of its offspring. 349 00:29:55,437 --> 00:29:58,770 The flames will also destroy all other plants 350 00:29:58,836 --> 00:30:00,569 from the surrounding area 351 00:30:02,741 --> 00:30:04,607 and this gives the Cistus 352 00:30:04,617 --> 00:30:07,989 the chance to extend its territory. 353 00:30:21,852 --> 00:30:23,168 From the ashes, 354 00:30:23,260 --> 00:30:27,614 a new generation of Cistus quickly rises. 355 00:30:32,625 --> 00:30:35,071 Cistus seeds escape damage 356 00:30:35,159 --> 00:30:39,044 because they are enclosed in flame-resistant capsules. 357 00:30:40,202 --> 00:30:43,738 Further more, the spurt stimulates their germination. 358 00:30:51,947 --> 00:30:54,157 It has taken millions of years 359 00:30:54,328 --> 00:30:58,497 for such complex adaptations as this to evolve. 360 00:30:59,839 --> 00:31:00,996 But today, 361 00:31:01,141 --> 00:31:03,575 plants of the dry zone and beyond 362 00:31:03,667 --> 00:31:05,967 face a new threat. 363 00:31:11,979 --> 00:31:15,083 From rainforests to mountain ranges, 364 00:31:15,333 --> 00:31:18,924 the evidence is that plants across the world 365 00:31:18,977 --> 00:31:21,935 are disappearing in variety and number 366 00:31:22,002 --> 00:31:25,843 faster than at any other time in the earth history. 367 00:31:30,960 --> 00:31:36,853 Human beings are taking over more and more of the world's wild places, 368 00:31:41,074 --> 00:31:46,099 but human intervention can also be the key to their future survival. 369 00:31:52,082 --> 00:31:55,227 Kew is at the forefront of the effort. 370 00:31:57,029 --> 00:32:00,502 Its unique facilities enable scientists here 371 00:32:00,595 --> 00:32:02,988 to both measure the loss of species 372 00:32:03,054 --> 00:32:07,367 and work out how to prevent extinctions before it's too late. 373 00:32:09,958 --> 00:32:12,393 And a crucial resource in that battle 374 00:32:12,406 --> 00:32:14,707 is held in this building - 375 00:32:15,944 --> 00:32:17,049 the Herbarium. 376 00:32:25,717 --> 00:32:28,887 Its collection of preserved and dried specimens 377 00:32:28,939 --> 00:32:34,253 contains samples of 90 percent of all known plant specimens on earth. 378 00:32:42,461 --> 00:32:44,619 Here, almost unbelievably, 379 00:32:44,709 --> 00:32:49,314 there are records of every single specimen ever sent to Kew. 380 00:32:49,722 --> 00:32:52,721 It was founded in 1853. 381 00:32:53,035 --> 00:32:57,114 Now, staff process about 50,000 specimens 382 00:32:57,127 --> 00:33:01,243 that are sent every year from all over the world. 383 00:33:02,191 --> 00:33:06,282 It contains about eight million specimens. 384 00:33:06,387 --> 00:33:10,069 It's the biggest repository of botanical data in the world 385 00:33:10,135 --> 00:33:13,069 and Kew's major weapon in the battle 386 00:33:13,240 --> 00:33:15,392 to save the plants of the planet. 387 00:33:19,238 --> 00:33:21,622 This vast databank 388 00:33:21,685 --> 00:33:26,181 plays a vital part in monitoring the global health of plants. 389 00:33:28,023 --> 00:33:30,772 It's run by curator David Mabberley. 390 00:33:31,233 --> 00:33:33,746 This herbarium, eight million specimens, 391 00:33:34,075 --> 00:33:38,548 is actually a record of the vegetation of the earth through time. 392 00:33:38,798 --> 00:33:41,361 There are something which had gone completely extinct 393 00:33:41,504 --> 00:33:45,783 and so all that is known of them is just some herbaria specimens. 394 00:33:45,860 --> 00:33:49,596 For example, this is a relation of the olive, 395 00:33:49,806 --> 00:33:54,002 which was known only from one island off the coast of California. 396 00:33:54,093 --> 00:33:56,275 And it hasn't been seen since 1873. 397 00:33:56,342 --> 00:33:56,907 Really? 398 00:33:56,908 --> 00:34:00,248 Even then, there were only three and that's all that we've got left now. 399 00:34:00,363 --> 00:34:01,196 Goodness! 400 00:34:01,563 --> 00:34:05,932 These specimens, though, are referred to, aren't they? For identification. 401 00:34:06,069 --> 00:34:07,530 Yes, these are the standards. 402 00:34:07,945 --> 00:34:11,620 And the ones which are in these red folders like this are actually the ones 403 00:34:11,856 --> 00:34:14,774 upon which the original description of a plant was made, 404 00:34:14,805 --> 00:34:16,420 the so-called type specimen. 405 00:34:16,528 --> 00:34:18,373 And therefore this is the kind of gold standard. 406 00:34:18,404 --> 00:34:21,710 If anybody really wants to know what is meant by a particular plant name, 407 00:34:21,741 --> 00:34:23,680 they must refer to the type specimen. 408 00:34:25,647 --> 00:34:30,384 The path to saving endangered species often begins here. 409 00:34:32,692 --> 00:34:36,567 For example, back in 1874, 410 00:34:36,813 --> 00:34:39,090 this specimen was sent back 411 00:34:39,352 --> 00:34:43,042 from the Island of Rodrigues in the Indian Ocean 412 00:34:43,380 --> 00:34:45,657 of a tree they called the Cafe Marron - 413 00:34:45,703 --> 00:34:47,842 a kind of coffee. 414 00:34:48,348 --> 00:34:50,285 It was preserved here, 415 00:34:50,286 --> 00:34:53,917 given a Latin name and put in the Herbarium. 416 00:34:54,517 --> 00:34:56,899 And then, about 50 years later, 417 00:34:57,022 --> 00:35:02,237 people on Rodrigues realized that Cafe Marron had disappeared. 418 00:35:03,620 --> 00:35:07,312 Then, in 1979, someone found a plant. 419 00:35:07,327 --> 00:35:10,004 Was it, was it not Cafe Marron? 420 00:35:10,389 --> 00:35:14,663 A specimen was sent here, compared with this specimen 421 00:35:14,956 --> 00:35:17,079 and indeed it proved with the case. 422 00:35:17,462 --> 00:35:19,938 So, for that single plant, 423 00:35:19,969 --> 00:35:24,323 a cutting was taken and sent here to Kew for propagation. 424 00:35:27,090 --> 00:35:28,982 From that single cutting, 425 00:35:29,089 --> 00:35:33,965 horticulturists grew a handful of clone specimens. 426 00:35:34,350 --> 00:35:36,442 But although they flowered frequently, 427 00:35:36,534 --> 00:35:39,525 they never produced viable seed. 428 00:35:40,841 --> 00:35:42,978 Without the ability to reproduce, 429 00:35:43,240 --> 00:35:46,115 the Cafe Marron was still doomed. 430 00:35:48,792 --> 00:35:51,451 So the plant earned the nickname 431 00:35:51,529 --> 00:35:53,405 "the living dead". 432 00:36:09,538 --> 00:36:12,123 The daunting challenge of rescuing it 433 00:36:12,185 --> 00:36:15,659 was taken up by endangered plant specialist - 434 00:36:15,706 --> 00:36:17,844 Carlos Magdalena. 435 00:36:23,719 --> 00:36:27,503 After several months of experimentation with heat and light, 436 00:36:27,641 --> 00:36:32,255 he finally managed to induce the plant to produce seed. 437 00:36:33,762 --> 00:36:35,285 But when they germinated, 438 00:36:35,393 --> 00:36:39,560 the young plants had leaves so unlike the Cafe Marron he knew, 439 00:36:39,606 --> 00:36:41,898 he thought he must have made a mistake. 440 00:36:45,021 --> 00:36:47,572 That's quite different from Cafe Marron. 441 00:36:47,604 --> 00:36:48,782 It's rather different, isn't it? 442 00:36:48,783 --> 00:36:51,235 Different color, different leaf shape. 443 00:36:51,664 --> 00:36:53,294 So, were you surprised? 444 00:36:53,341 --> 00:36:57,187 Well, I was surprised in the way that I've never seen them before. 445 00:36:59,124 --> 00:37:03,676 This strange plant looks nothing like the herbaria sample. 446 00:37:04,644 --> 00:37:08,629 At first, nobody could be sure that was even the same species. 447 00:37:11,412 --> 00:37:12,982 But as it grew, 448 00:37:13,135 --> 00:37:14,628 it changed 449 00:37:14,888 --> 00:37:17,232 and eventually, it morphed 450 00:37:17,233 --> 00:37:20,655 into a recognizable adult plant. 451 00:37:22,255 --> 00:37:25,111 But what is the reason for this dramatic change 452 00:37:25,230 --> 00:37:27,578 as the Cafe Marron matures? 453 00:37:31,149 --> 00:37:34,621 The answer is camouflage. 454 00:37:36,820 --> 00:37:40,251 This is the most famous inhabitant 455 00:37:40,252 --> 00:37:43,315 of the Island of Rodrigues - 456 00:37:43,665 --> 00:37:46,064 a giant tortoise. 457 00:37:46,602 --> 00:37:49,184 It loves bananas. 458 00:37:51,576 --> 00:37:52,523 Go on. 459 00:37:54,045 --> 00:37:56,957 But they also likes green leaves 460 00:37:56,970 --> 00:37:59,246 and that's their main food. 461 00:38:02,071 --> 00:38:05,085 So any plant growing close to the ground 462 00:38:05,387 --> 00:38:07,755 has very little chance of survival 463 00:38:07,899 --> 00:38:12,148 while creatures like this are going around eating them. 464 00:38:12,515 --> 00:38:16,685 And that's the clue to the mystery of the Cafe Marron. 465 00:38:17,461 --> 00:38:20,724 When it's small, it produces leaves 466 00:38:21,105 --> 00:38:24,512 that are very thin and not even green. 467 00:38:24,565 --> 00:38:28,103 And the tortoise whose eyesight is not very good 468 00:38:28,247 --> 00:38:29,800 doesn't even see it. 469 00:38:29,852 --> 00:38:34,614 So he takes very little notice of leaves like these 470 00:38:35,114 --> 00:38:37,718 and the Cafe Marron can grow. 471 00:38:38,284 --> 00:38:39,547 As it grows, 472 00:38:39,902 --> 00:38:41,771 it becomes a bit bigger 473 00:38:42,086 --> 00:38:43,243 and still 474 00:38:43,667 --> 00:38:46,938 its leaves are thin and dark 475 00:38:46,978 --> 00:38:48,845 and rather inconspicuous. 476 00:38:49,332 --> 00:38:51,516 And it's not until 477 00:38:52,976 --> 00:38:55,067 it's really quite tall 478 00:38:55,712 --> 00:39:00,171 does the Cafe Marron plant produce its proper green leaves 479 00:39:00,461 --> 00:39:01,722 and its flowers. 480 00:39:01,802 --> 00:39:02,919 But by that time, 481 00:39:03,024 --> 00:39:07,576 it's well beyond the reach of a giant tortoise. 482 00:39:08,076 --> 00:39:10,536 So that is the solution 483 00:39:10,693 --> 00:39:12,495 to the Cafe Marron mystery 484 00:39:12,508 --> 00:39:15,205 that the plant produces two different leaves 485 00:39:15,376 --> 00:39:17,797 as a defense of being eaten. 486 00:39:30,476 --> 00:39:32,475 The Cafe Marron's survival 487 00:39:32,633 --> 00:39:36,238 is tribute to the skills developed here in Kew. 488 00:39:40,235 --> 00:39:43,656 But it is just one species. 489 00:39:45,931 --> 00:39:50,539 The ultimate aim is to safeguard all remaining plant species. 490 00:39:53,783 --> 00:39:56,033 And the maybe-way of doing that 491 00:39:56,059 --> 00:39:59,848 by using these extraordinary structures - 492 00:40:00,532 --> 00:40:01,716 seeds. 493 00:40:06,081 --> 00:40:11,198 A 3D microscope magnifies them up to 200 times 494 00:40:11,211 --> 00:40:13,948 and reveals how extraordinary complex 495 00:40:14,040 --> 00:40:16,316 the surface of a seed can be. 496 00:40:23,496 --> 00:40:26,219 No two species are the same. 497 00:40:28,706 --> 00:40:31,349 These images have been given artificial colors, 498 00:40:31,454 --> 00:40:35,005 but many of their shapes are beyond explanation. 499 00:40:36,742 --> 00:40:39,938 Some structures, however, have a clear function. 500 00:40:39,964 --> 00:40:43,727 They help the seed to achieve one of its main purposes - 501 00:40:43,767 --> 00:40:44,977 to travel. 502 00:40:46,106 --> 00:40:49,725 Many seeds rely on animal couriers. 503 00:40:50,106 --> 00:40:51,737 The American Stickseed 504 00:40:51,750 --> 00:40:55,103 attaches itself to the fur or skin of passing animals 505 00:40:55,170 --> 00:40:57,405 with hooks or barb spikes. 506 00:40:59,588 --> 00:41:02,720 The amazing sticking structures of such hitchhikers 507 00:41:02,786 --> 00:41:05,206 inspired the invention of Velcro. 508 00:41:07,389 --> 00:41:10,875 Some seeds carry a little package of nutritious fat 509 00:41:10,967 --> 00:41:15,215 which persuades an ant to take it back to its underground nest 510 00:41:15,294 --> 00:41:19,135 where the seed having surrendered its fatty reward to the ants 511 00:41:19,320 --> 00:41:21,292 can germinate in safety. 512 00:41:24,094 --> 00:41:26,671 The seeds of orchids are miniscule 513 00:41:26,724 --> 00:41:28,806 and produced in their millions. 514 00:41:30,131 --> 00:41:33,087 They blow away like dust. 515 00:41:34,631 --> 00:41:39,168 In contrast, this much bigger seed has a large flat membrane 516 00:41:39,247 --> 00:41:40,984 which serves as a wing 517 00:41:41,010 --> 00:41:44,758 so that it can float great distances on the wind. 518 00:41:47,113 --> 00:41:50,441 Other wind disperse seeds like the yellow paintbrush 519 00:41:50,467 --> 00:41:52,584 have a honey cone texture. 520 00:41:54,253 --> 00:41:56,160 Such complex sculpturing 521 00:41:56,161 --> 00:41:59,292 enables seeds to catch the slightest wind current 522 00:41:59,319 --> 00:42:00,989 and ride thermos 523 00:42:01,002 --> 00:42:04,278 traveling long distances from their mother plants. 524 00:42:06,896 --> 00:42:09,196 But these images also reveal 525 00:42:09,209 --> 00:42:13,760 the incredible toughness of the seed's outer capsule. 526 00:42:14,484 --> 00:42:16,576 This strength's maybe the key 527 00:42:16,681 --> 00:42:19,601 to the survival of all plants 528 00:42:20,286 --> 00:42:24,099 for seeds can survive all kinds of hardship. 529 00:42:26,821 --> 00:42:28,873 This plant is called the pincushion. 530 00:42:28,874 --> 00:42:30,952 and grows in South Africa. 531 00:42:32,136 --> 00:42:35,965 And this individual specimen is something of a miracle. 532 00:42:38,593 --> 00:42:40,804 In 1803, 533 00:42:41,133 --> 00:42:44,882 a British man of war captured a Dutch merchantman 534 00:42:45,132 --> 00:42:47,447 coming back from the Cape of Good Hope. 535 00:42:47,933 --> 00:42:52,076 And on board, in the cargo, they found a pack of seeds. 536 00:42:52,668 --> 00:42:53,824 When they got back to Britain, 537 00:42:53,825 --> 00:42:57,824 the seeds went to the trial of London for quite a long time. 538 00:42:58,061 --> 00:43:01,652 But eventually, they found their way here to Kew. 539 00:43:02,442 --> 00:43:03,692 And one of them, 540 00:43:04,072 --> 00:43:07,597 germinated and produced this plant 541 00:43:07,807 --> 00:43:09,622 after 200 years, 542 00:43:09,885 --> 00:43:15,319 just shows how long seeds can survive even without help. 543 00:43:18,291 --> 00:43:20,461 This ability to endure 544 00:43:20,500 --> 00:43:24,973 has inspired Kew's latest ground-breaking project. 545 00:43:35,232 --> 00:43:38,468 Its ultimate goal is to ensure the survival 546 00:43:38,481 --> 00:43:42,212 of every remaining species of plant on earth. 547 00:43:44,044 --> 00:43:46,583 The work takes place deep underground 548 00:43:46,609 --> 00:43:48,964 in a labyrinth of sealed vaults 549 00:43:48,978 --> 00:43:52,371 that are encased in steel and concrete. 550 00:43:57,369 --> 00:44:00,920 It's called the Kew Millennium Seed Bank. 551 00:44:03,498 --> 00:44:06,077 Its contents are so valuable 552 00:44:06,156 --> 00:44:09,445 that it was specifically designed to withstand the impact 553 00:44:09,537 --> 00:44:12,128 of a bomb or an air crash. 554 00:44:12,745 --> 00:44:15,100 Inside these vaults, there are seeds 555 00:44:15,257 --> 00:44:17,875 gathered from plants all over the world. 556 00:44:18,480 --> 00:44:23,795 In fact, as much as 10 percent of the world's known species 557 00:44:24,611 --> 00:44:26,319 are represented in there. 558 00:44:50,509 --> 00:44:52,871 The heart of the Seed Bank Project 559 00:44:52,941 --> 00:44:55,086 is this gigantic freezer 560 00:44:55,099 --> 00:44:58,426 full of seeds in sealed jars. 561 00:45:00,676 --> 00:45:05,043 The conditions inside are perfect for long term storage. 562 00:45:07,989 --> 00:45:11,764 But the job is aided by the very nature of seeds. 563 00:45:13,579 --> 00:45:17,183 The seed is the stage in which a plant can remain dormant 564 00:45:17,341 --> 00:45:20,854 waiting until conditions for germination are right. 565 00:45:25,602 --> 00:45:29,376 Inside the seed, there is a store of food. 566 00:45:29,652 --> 00:45:33,034 Outside, there's a tough protective shell 567 00:45:33,073 --> 00:45:35,847 to guard against predation or damage. 568 00:45:36,202 --> 00:45:39,794 In fact, the seed is a kind of time capsule 569 00:45:39,926 --> 00:45:42,293 that can live for sometimes a decade, 570 00:45:42,320 --> 00:45:44,463 sometimes even centuries. 571 00:45:44,766 --> 00:45:46,503 The aim of the Seed Bank 572 00:45:46,556 --> 00:45:49,527 is to prolong that period as long as possible. 573 00:45:49,750 --> 00:45:50,882 To do that, 574 00:45:51,092 --> 00:45:53,013 they clean the seeds, 575 00:45:53,263 --> 00:45:54,262 dry them, 576 00:45:54,420 --> 00:45:56,657 put them in jars like this, 577 00:45:57,183 --> 00:46:01,681 and then keep them here at minus 20 degrees centigrade. 578 00:46:01,982 --> 00:46:05,509 How long they will survive under these conditions? 579 00:46:05,601 --> 00:46:06,784 Nobody knows, 580 00:46:06,955 --> 00:46:10,560 but it's certainly going to be for a very long time. 581 00:46:14,137 --> 00:46:17,701 New samples arrive for the Seed Bank everyday. 582 00:46:20,253 --> 00:46:24,240 They are first identified and studied in microscopic detail 583 00:46:24,292 --> 00:46:27,897 by chief morphologist Dr. Wolfgang Stuppy. 584 00:46:29,947 --> 00:46:33,104 The latest report from Israeli paints that 585 00:46:33,340 --> 00:46:38,853 date palm seeds have been found in King Herod the Great's palace in Masada 586 00:46:38,879 --> 00:46:42,338 and they germinated after 2,000 years. 587 00:46:42,510 --> 00:46:45,112 So that is possible and this is 588 00:46:45,349 --> 00:46:48,993 the principle that naming "Seed Bank" is built upon. 589 00:46:48,994 --> 00:46:52,348 that seeds can survive for millennium if necessary. 590 00:46:55,177 --> 00:46:58,450 The longevity of most kinds of seeds is unknown, 591 00:46:59,648 --> 00:47:02,330 so they must be regularly checked. 592 00:47:09,053 --> 00:47:14,024 Samples of seeds are periodically removed from the vaults and germinated 593 00:47:35,857 --> 00:47:37,501 If most grow, 594 00:47:37,555 --> 00:47:41,771 the whole batch will be left in the vaults for another decade. 595 00:47:46,394 --> 00:47:49,381 And sometimes a sample fails, 596 00:47:50,039 --> 00:47:51,589 like these anemone seeds, 597 00:47:51,602 --> 00:47:54,956 which, although germinating in sterilized conditions, 598 00:47:54,983 --> 00:47:57,496 become chocked with fungus. 599 00:48:05,413 --> 00:48:06,650 When this happens, 600 00:48:06,716 --> 00:48:09,622 the scientists must find out why 601 00:48:09,741 --> 00:48:12,136 and how to prevent it from happening again. 602 00:48:17,211 --> 00:48:20,619 The Seed Bank Project is still in its infancy 603 00:48:21,934 --> 00:48:25,605 but the evidence is that there is no time to lose. 604 00:48:27,486 --> 00:48:30,406 There are already seeds stored here from plants 605 00:48:30,485 --> 00:48:33,155 that are now extinct in the wild. 606 00:48:34,389 --> 00:48:36,967 The problem is, well, many people don't understand, 607 00:48:37,060 --> 00:48:39,574 is that if a species got extinct, 608 00:48:40,059 --> 00:48:43,349 it means it's gone for us forever. 609 00:48:43,823 --> 00:48:47,096 There were five mass extinctions in the earth history. 610 00:48:47,544 --> 00:48:49,282 After every mass extinction, 611 00:48:49,306 --> 00:48:51,963 it took between 4 and 20 million years 612 00:48:51,964 --> 00:48:55,226 for biodiversity to bounce back to pre-extinction levels. 613 00:48:56,121 --> 00:48:59,712 Now, clearly we cannot wait four million years 614 00:48:59,947 --> 00:49:03,143 for life to bounce back. 615 00:49:03,827 --> 00:49:05,892 So if we don't keep seeds here 616 00:49:06,168 --> 00:49:08,471 and this plant species got extinct, 617 00:49:08,866 --> 00:49:12,273 it will be lost to mankind forever. 618 00:49:15,889 --> 00:49:18,203 Thankfully, there is a great momentum 619 00:49:18,244 --> 00:49:20,716 behind the Seed Bank Project. 620 00:49:22,519 --> 00:49:24,386 Over the next a few decades, 621 00:49:24,544 --> 00:49:28,031 these shelves will be filled to capacity. 622 00:49:36,566 --> 00:49:39,880 There's enough space here to hold seed 623 00:49:39,972 --> 00:49:44,642 from every single species of plants on this planet. 624 00:49:45,445 --> 00:49:48,456 But this place is not just an insurance policy 625 00:49:48,472 --> 00:49:50,877 against the ultimate apocalypse. 626 00:49:51,219 --> 00:49:54,350 This is of huge value right now. 627 00:49:54,532 --> 00:49:56,202 For whatever we discover 628 00:49:56,203 --> 00:49:59,717 that a plant is teetering on the brink of extinction, 629 00:49:59,927 --> 00:50:04,084 we can now boost its numbers with seeds from here 630 00:50:04,150 --> 00:50:09,919 and so ensure that no plant species on earth need go extinct. 631 00:50:20,893 --> 00:50:22,601 There are an estimated 632 00:50:22,602 --> 00:50:26,522 400,000 different species of plant on the planet. 633 00:50:27,851 --> 00:50:32,403 We can't possibly understand the lives of each and every one of them. 634 00:50:34,863 --> 00:50:38,083 But here at the Royal Botanic Gardens in Kew, 635 00:50:38,241 --> 00:50:41,101 one of the birth places of scientific botany, 636 00:50:41,280 --> 00:50:45,227 we began to glimpse their extraordinary world. 637 00:50:49,869 --> 00:50:53,670 Kew is still in the forefront of botanical research 638 00:50:53,749 --> 00:50:57,314 helping to ensure that we not only understand plants, 639 00:50:57,367 --> 00:51:01,406 but protect them in all their astonishing variety. 640 00:51:07,784 --> 00:51:09,467 And here, we can see 641 00:51:09,494 --> 00:51:13,231 how plants in all habitats and environments 642 00:51:13,349 --> 00:51:16,478 are intricately connected with animals 643 00:51:18,333 --> 00:51:20,031 and with fungi. 644 00:51:21,345 --> 00:51:25,489 Not only do plants give the world much of its beauty, 645 00:51:26,277 --> 00:51:29,354 they are indeed the very basis 646 00:51:29,434 --> 00:51:32,342 of all life on earth.