Over the millennia, people have learned through trial and error, which Plants are safe for consumption and which are best to avoid. Some of these plants can snuff out your life as surely as a poisonous snake. [VIDEO] Some of them have a deadly effect just by staying around them, without having any physical contact with them. Here are six of the earth’s deadliest plants.

1. Little Apple of Death

This is the world’s most dangerous tree. Both the tree and its fruits look dangerously similar to that of an apple. For this reason, people easily mistake it for an apple and feel tempted to eat the fruit. All parts of this tree are extremely dangerous.

The fruits which are described as sweet and tasty are extraordinarily toxic. Eating them can cause inflammations, blistering around the mouth and intestinal issues, and a violent death. People are advised not to touch, near or even stand under the tree because of its deadliness. This tree is also known as Manchineel.

2. Suicide Tree

This beautiful looking deadly tree is a perfect murder weapon. The kernels of this tree contain a potent heart toxin known as cerebin, and can easily be disguised if they are crushed and mixed with spicy foods. Surprisingly, pathologists cannot identify poisoning caused by this plant unless there is evidence the victim had eaten the suicide plant. This plant is also known as Otalanga or Pong-pong.

3. Castor oil plant

This is one of the dangerous plants that pose a great risk to human and animal health.

The seeds which are used for making the popular Castor Oil contain a potent poison that damages animal tissue. Ricin poisoning includes burning sensation in the mouth, nausea, dehydration, reduced urination, and death.

4. Wolfsbane

This plant is extremely toxic. Poisoning from this plant causes gastrointestinal upset and slows down the heart rate. The effect is usually fatal. The poison of this plant is so toxic, such that it was once used to kill wolves. It is used to create poison arrows used during hunting and wars. This plant is also known as Queen of poison or Devil’s helmet.

5. Oleander

All parts of this plant are deadly to human and animals as well. Touching the plant results in skin irritation. Eating the flower could cause heart attack and death. Ingesting any part of this plant can be fatal. Stay away from this plant while burning it, to avoid the deadly effect of its smoke.

6. Hemlock

This highly toxic herb causes a slow and painful death when eaten. Its leaves are similar to that of celery. Hemlock is one of the deadliest plants in existence. Many years ago, tea made from this plant was used as one of the modes of execution. It is the poisonous plant responsible for the death of the famous Socrates. Touching this plant won't cause harm. It can only be deadly when eaten.