1. Most likely to eat a rat

Giant Pitcher Plant: Nepenthes attenboroughii

Discovered more than 5000 feet above sea level on Mount Victoria in the Philippines, the giant, carnivorous pitcher plant secretes a nectar-like substance to lure unsuspecting prey into a pool of enzymes and acid. A series of sticky, downward ribs makes it nearly impossible for trapped prey to escape. The plant's 30-centimeter diameter is large enough to trap unlucky rodents, but insects are its most common meal. Pitcher plants, of which there are about 600 different species, tend to grow in nitrogen-deficient environments, and therefore get their nutrients from decaying victims.

2.Castor Bean Plant: Ricinus communis

Castor-bean plants can be purchased at just about any garden center, despite containing the deadly poison ricin. Concerned gardeners can simply pluck the seeds off the plant, which is where the ricin is stored. Though the process to extract enough ricin and process it into a weapon is complex, yet it is known that  it was used  to permanently silence opposition.

3. Most violently toxic plant in North America

Western Water Hemlock: Cicuta douglasii

Deemed the most "violently toxic plant that grows in North America" the water hemlock contains the toxin cicutoxin, which wreaks havoc on the central nervous system, causing grand mal seizures==which include loss of consciousness and violent muscle contractions==and eventually death, if ingested. Water hemlock is different from poison hemlock, Socrates' notorious killer, in that it contains coniine alkaloids that kill by paralyzing the respiratory system. Both are members of the carrot family.

4. The plant that killed a president's mother

White snakeroot: Eupatorium rugosum

Drinking milk from a cow that decided to chow down on white snakeroot could lead to deadly milk sickness, as was the case with Abraham Lincoln's mother Nancy Hanks. Every part of this perennial plant contains tremetol, an unsaturated alcohol that can cause muscle tremors in livestock before killing them. People were trying desperately throughout the 19th century to figure out what was poisoning their animals. It wasn't understood until the turn of the century, when the U.S. Department of Agriculture pinpointed the cause and quickly got the word out. Now, white snakeroot still grows wild, but more control in the agricultural industry has helped to prevent cows from eating it.

5. Monkshood: Aconitum napellus

 The vibrant purple plant, commonly found in backyard gardens, is loaded with the poisonous alkaloid aconite, which tends to cause asphyxiation. Anyone who has this plant in their garden must wear gloves when handling it.

6. Most gruesome killer

Common Bladderwort: Utricularia macrorhiza
This aquatic meat eater relies on several submerged bladders to capture prey such as tadpoles and small crustaceans. An unsuspecting passerby will brush against an external bristle-trigger, causing the bladders to spring open and capture it. Once inside, the victim dies of suffocation or starvation and then decays into a liquid that is sucked up by cells on the walls of the bladder.

7. Most animal-like

Venus flytrap: Dionaea muscipula

With the ability to clamp shut in a half-second, the Venus flytrap's reaction time seems fit for the animal kingdom. Insects need to touch two of the flytrap's hairs consecutively in order for the plant to react, but the precise mechanism that shuts the trap remains unclear. It seems that when the plant is touched, the electrical potential of the leaf is altered, triggering a host of cellular-level events.

8. The most likely plant to turn a person into a zombie

Angel Trumpet: Brugmansia

The droopy, gorgeous angel trumpet, native to regions of South America, packs a powerful punch of toxins, containing atropine, hyoscyamine, and scopolamine. As documented in the 2007 VBS.tv documentary "Colombian Devil's Breath," criminals in Colombia have extracted scopolamine from the plant and used it as a potent drug that leaves victims unaware of what they are doing but entirely conscious. Scopolamine can be absorbed through the skin and mucous membranes, allowing criminals to simply blow the powder in a person's face. The documentary is filled with scopolamine-related horror stories, including one account of a man moving all of his possessions out of his apartment (and into the hands of his robbers) without remembering any of it.

9. The most enticing poison

Oleander: Nerium oleander

This extremely common evergreen shrub is one of the most poisonous plants in the world.  The leaves, flowers and fruit contain cardiac glycosides, which have therapeutic applications but are likely to send someone into cardiac arrest should he eat part of the plant. It is heard  that there is a woman in California currently on death row for trying to poison her husband with the plant, and two young boys were found dead after ingesting oleander a few years back. People tend to be blasé, because the flowers are bright and pretty, sort of candy-colored. But it is a very poisonous plant that will stop your heart.

10. Best home-security system

Mala Mujer: Cnidoscolus angustidens

                                                                                                                                                                  
This garden plant is described as more painful than poisonous. Mala mujer, which translates to "bad woman," can be found in parts of the southwest and Mexico and is covered with nasty thorns, which could be turned into makeshift barbwire if needed. The real danger, however, comes from the caustic, milky sap that can leak from the plant. The sap, a common feature among many plants in the Euphorbia genus, can cause painful skin irritations and unsightly discoloration.  

Source  PopularMechanics.com

http://www.popularmechanics.com/home/improvement/lawn-garden/4331026