The castorbean plant is a species of flowering plants with the scientific name (Ricinus communis). It is best known for being the plants from which castor oil is derived and is therefore also known as the castor oil plant. The protein toxin known as ricin is also isolated from the seeds of the Castorbean plant.
This plant's size varies depending upon which area it grows in. For example, it can grow to be a tree around thirty to forty feet high in favorable tropical regions. It's narrower size measures ten to fifteen feet high in warm Mediterranean countries such as Egypt, Greece and Algeria. In northern countries, the Castor Oil plant grows to a height of four to five feet tall. It is a shrub with thick, cylinder-shaped stems and a purple top. 
The leaves of the Castorbean plant grow palmately, or with four or more leaflets sprouting from the stem. They span from six to eight inches across with sharp, jagged ends. Their color changes from a brilliant red to a bluish green as they grow older. Concerning the reproductive system, the Castor Oil plant has both male and female parts that develop on a spike. The male flowers are on the underside of the spike and have unique characteristics. They have a calyx, the outermost parts of the flower, which contains much yellow stamina. The female part is located on the higher section of the plant and, like the male flower, has no corolla. The calyx of the female flower has a reddish hue and the ovary in the middle is surrounded by separated red styles. Its fruit is a green, uneven pod, not even an inch long, with soft spikes all around it. Though the seeds have many different shapes and sizes depending on their derivation, the average look of a Castor Oil seed is usually condensed and oval-shaped. The littler plants produce smaller seeds, whereas the tall trees bear larger seeds. The seed has a tough, grayish brown covering, but inside it has a thinner, more delicate layer. These seeds hold a poisonous material that could cause potential harm. They can be extremely lethal.
- Main Article: Castor oil
Castor Oil is first seen in the time of the ancient Egyptians where it was used for medical purposes.  A man by the name of Herodotus discovered this plant during the period of ancient Egypt. He called it Kiki, which was used as a furnishing by the Egyptians in their tombs where they also used the seeds of the plant. It is assumed that the plant had already been distributed throughout Greece, who still produces it. In the Bible, the book of Jonah talked of a gourd called the Kikajon which is also concluded to be the one and the same Ricinus communis. It is mentioned to have been used by the Egyptians, not only as furnishings, but as lamp oils and ointments. A man named Dioscorides describes the manufacturing of the Castor oil plant and its medicinal value. It is also known that it was used as a purgative back then as well. Throughout the Middle Ages and in Europe, the Bishop of Ratisbonhad grew it within the thirteenth century, but it was abandoned for a while. In 1597, a different man named Gerard called it Oleum cicinum and wrote that it was administrated to people for skin diseases. In Europe, the use of the plant for medicine had almost altogether faded away and instead, the supplies needed in order to make Castor Oil came specifically from Jamaica. From there, the plant’s name came from the word Agnus Castus. Its scientific name originated from the Latin word Ricinus, which means dog-tick.
- Castorbean by the U.S. Department of Agriculture
- Castor Oil Plant A Modern Herbal, Mrs. M. Grieve, Botanical.com
- Castor Oil American Cancer Society