Plants seem so passive. Tree branches bow to the wind, losing their leaves. Lettuce just sits there as snails help themselves to a free salad bar. And grass lets everyone walk all over it.

But all that apparent listlessness is deceptive. In truth, plants are incredibly active members of their communities. Plants move on their own all the time—creeping, digging, reaching, blooming. However, most of the action happens too slowly for our eyes to see unaided. In his 1995 documentary series The Private Life of Plants, David Attenborough and his crew created beautiful time-lapse videos to showcase plants' hidden mobility. Climbing jungle vines race one another up tree trunks, stretching towards the sunlight. The thorny bramble whips from side to side, shoving competing plants out of the way to expand its territory.

» View a slideshow of the plant kingdom's most unusual talents

A spindly orange vine known as dodder is a particularly striking example of dynamic plant life. Dodder is a parasite—it lives off of other plants. Instead of waiting around for a suitable host, the vine hunts one down. Conseulo De Moraes of Penn State University planted a young dodder near a tomato plant and continuously filmed the pair for several days. Her time-lapse video reveals a growing dodder flailing around, tasting the air like a snake, until it finally brushes the tomato's stem and begins to encircle its victim. Eventually it would sink tiny nozzles into the tomato plant to suck out vital juices.

De Moraes discovered something surprising about the dodder: it can smell. The vine sniffs out its hosts, growing toward telltale chemicals released by its neighbors. And it is picky. Dodder prefers juicy tomato plants to slender wheat and healthy plants to sick plants. Tel Aviv University biologist Daniel Chamovitz discusses dodder and many other fascinating plants in his upcoming book, What A Plant Knows, an excerpt from which appears in the May issue of Scientific American.

Dodder is hardly the only plant whose mobility and abilities would surprise most people. The plant kingdom is full of unusual talents that are more common than biologists first realized. The Venus flytrap is only one of several different kinds of carnivorous plants that have developed astonighing ways to catch and digest insects and other small animals. Almost all plants have evolved chemical defenses against herbivores and many plants recognize when their neighbors are under attack, preparing for battle themselves. Alpine buttercups track the sun's arc over the course of a day to keep their blossoms warm and appealing to heat-seeking pollinators. The telegraph plant swivels its leaves to maximize exposure to sunlight, adjusting so quickly that you can see the leaves moves in real time. Some plants may even distinguish between family and strangers, sharing resources only with the former.

» View a slideshow of the plant kingdom's most unusual talents

Like most organisms, plants sense and respond to their environments. To appreciate just how sensible plants are, we have to look at the world—or even smell the world—from their perspective

8 Comments

1. 1. jvkohl 10:32 AM 4/21/12

   Human pheromones and food odors: epigenetic influences on the socioaffective nature of evolved behaviors. Socioaffective Neuroscience & Psychology 2012, 2: 17338 details the molecular mechanisms involved in the calibration of individual survival by nutrient chemicals, and their metabolism to pheromones that promote species survival in species from microbes to man. The concept of chemical signalling important to plants can be viewed in the context of what occurs in every species because the molecular biology of life is the same.
   

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2. 2. harris 05:19 AM 5/24/12

   Marvellous to know that the Venusfly-trap has hair to detect insects . Reminds me of insect sensillae.

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3. 3. Michelle de Villiers 02:41 PM 5/25/12

   That doddery dance needs to be set to music! -typo on 'astonighing' :)

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4. 4. R T Nicholson 10:32 AM 5/26/12

   Has anyone checked the root system of the dodder to see if they may launch a two pronged attack against their host/victim?

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5. 5. poeteye 03:14 PM 5/27/12

   FLORAL ATTRACTION
   -- James Ph. Kotsybar
   
   Flowers have fragrances that we can’t smell
   and colors and patterns that we can’t see;
   their pheromones make insect passions swell,
   and UV marks can hypnotize a bee.
   Who says that flowers can’t be chefs gourmet,
   tantalizing both butterfly and slug?
   What tactile pleasures come through antennae
   from a surface specific to some bug?
   Flowers have a broader range than do we
   of the visual and olfactory --
   a greater access to life’s energy --
   so maybe, too, other things sensory.
   Perhaps they call to us with ESP
   or siren song we hear unconsciously.
   
   
   
   SIDEBAR
   The scent of chocolate is not generally a favorite of insects. In fact, husks from the plant are used as a garden mulch to deter insects. However, there is a hybrid orchid now popular in horticulture (Oncidium Sharry Baby) that has the scent of cocoa. I submit that this plant produces this fragrance for its newest of pollinators (mankind), showing that it has some awareness of its domesticated situation. After all, insects only pollinate species, but an orchid hybridized by man that has "learned" to smell like a human's favorite food, gets pollinated, cultivated, watered, fertilized and generally pampered under conditions ideal to its growth.

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6. 6. Mimosa Pudica 08:37 AM 6/6/12

   The sensitive plant or more commonly know in classrooms as the TickleMe Plant responds by closing its leaves and lowering its branches when Tickled.
   http://www.sensitiveplant.com It is the one plant every one should grow.

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7. 7. Mimosa Pudica in reply to harris 08:41 AM 6/6/12

   Yes and even more amazing to me is the TickleMe Plant that will suddenly closes its leaves when Tickled yet won't hurt a fly. Search TickleMe Plant to see it in action or to grow your own.

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8. 8. Mimosa Pudica 08:13 PM 1/29/13

   Here is a TickleMe Plant in action
   <a href="TickleMe" target="_blank"http://www.Ticklemeplant.com">TickleMe Plant</a>

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