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Petunias and potatoes added to list of carnivorous plants

New review on carnivorous flora suggests that a number of plants previously thought innocent may actually be murderous.
By Bryan Nelson
Wed, Dec 09 2009 at 5:36 AM EST
Read more: ECOLOGY, NATURE, WILDERNESS

KILLER PETUNIAS: Although petunias don't digest the insects they catch, they likely use the dead bugs as fertilizer. (Photo: marilynnm63/Flickr)
 
That's according to a new review on carnivorous plants which suggests that a number of commonplace, garden-variety plants like petunias and potatoes deserve to be classified as meat-eaters just like the Venus flytrap and pitcher plants.
 
The review looked at all the research so far on carnivorous plants and found that what constitutes carnivory in plants has historically been vague and loosely defined. While only a handful of flora directly digest the bugs they catch, a wide variety of other plants possess mechanisms which allow them to go about their murderous business in a subtler manner than their more conspicuous cousins.
 
For instance, petunias and potatoes have sticky hairs that trap insects, and some species of campion have the common name of 'catchfly' for the same reason. They don't immediately digest their prey, but the animals they ensnare eventually breakdown in the surrounding soil, providing nutrients that can be absorbed through the roots.
 
"Many commonly grown plants may turn out to be cryptic carnivores, at least by absorbing through their roots the breakdown products of the animals that they ensnare," said Chase.
 
At present scientists widely recognize at least six different kinds of killer plants, all of which typically kill in order to supplement their hunger for nitrogen and phosphorus in nutrient-poor habitats. Plants like petunias and potatoes are essentially doing the same thing, just in a more sinister way. Rather than devouring their prey immediately, they are using their victims' bodies as fertilizer. 
 
"What plants are doing is much more sophisticated than we ever imagined," Chase told Livescience. "Although animals are eating plants, plants are also eating animals. It's not just a one-way street."


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Comments(7)

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Posted By DSE - Tue, Jan 12 2010 at 2:12 PM EST

Huh?

How exactly does the potato plant "murder" its prey? It woudl seem that almost all plants benefit from decaying insects and animals. That is hardly "sinister."

Posted By Neumadir - Mon, Dec 14 2009 at 11:53 AM EST

This goes a long ways towards explaining...

.... the potato and petunia garden that is currently ravaging the pet cemetery in our back yard.

Posted By Kupac - Mon, Dec 14 2009 at 11:47 AM EST

Not convinced

Intriguing idea, but it should be argued more in detail.

Plants are rarely alone, so the neighboring (possibly competing) plant would also benefit from the dead insect in the ground; and not necessarily less than the one doing all the work of capturing and killing the insect.

How about ants and other scavengers that clean up the body of the dead insect before it disintegrates in the soil? They can transport the insects to their nest, which would bring no advantage to the plant.... More

Posted By Tony - Mon, Dec 14 2009 at 9:02 AM EST

They'd eat us too, if they could!

So, if a potato plant lasts only one season, how long does it take an insect to break down and the nutrients become accessible to the plant?

Posted By momz - Sun, Dec 13 2009 at 5:46 PM EST

Sexual Encounters of the Floral Kind.

A great video made by 5 Cambridge hort studies as their final thesis work explains the many different techniques plants use to attract pollinators. It is really incredible and so very very entertaining. It is called "Sexual encounters of the Floral Kind." Libraries carry it. I agree murderous is not appropriate.

Posted By Brittany - Thu, Dec 10 2009 at 5:15 PM EST

Strange

"Murderous" is a pretty strange word choice for plant behavior. Are you really saying that a plant can have "conspicuous" and "sinister" intent? Maybe try a more objective approach to reporting on discoveries in the scientific community.

Posted By Anonymous - Mon, Dec 14 2009 at 10:56 AM EST

GartenGrl

Huh, that is quite interesting...not really such a surprise...and explains why Petunias are so sticky....
GartenGrl

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