Yes
Overview. Castor bean plants are prized for their aesthetic value in the home garden, but they come with a hefty warning. Castor beans are highly toxic--they contain the deadly poison ricin--and can kill if ingested and will cause irritation when touched. The castor bean plant (Ricinus communis) is a perennial shrub with multi-lobed, toothed leaves and tiny green, clustered, inconspicuous flowers.  Deadly Caster Bean. The caster bean plant, Ricinus communis, is a native of tropical Africa and is grown in many gardens in North America for its fabulous large leaves. Here in zone 5 it is an annual that can grow to 5 feet in one season. The caster bean plant itself is not poisonous to humans, but the seeds are. The seeds contain a protein called ricin and there is no question that ricin is very poisonous to humans, animals and even insects. The caster bean holds the Guinness Book of World Records title for the world’s most poisonous plant, due to Rici Ricinus communis, the castor oil plant, is a species of flowering plant in the spurge family, Euphorbiaceae. It is the sole species in the monotypic genus, Ricinus, and subtribe, Ricininae. The evolution of castor and its relation to other species are currently being studied using modern genetic tools. Castor seed is the source of castor oil, which has a wide variety of uses. The seeds contain between 40% and 60% oil that is rich in triglycerides, mainly ricinolein. The seed also contains ricin, a water-soluble toxin, which is also present in lower concentrations throughout the plant. The castor bean plant, ricinus commanis, is an ornamental plant whose leaves range from auburn to green and whose flowers are infused with colors from red to pink. Inside the spiny fruit of the castor bean plant are mottled seeds containing ricin, poisonous when ingested.  The toxicity of raw castor beans is due to the presence of ricin. Although the lethal dose in adults is considered to be four to eight seeds, reports of actual poisoning are relatively rare. According to the 2007 edition of Guinness World Records, this plant is the most poisonous in the world. Castor seed is the source of castor oil, which has a wide variety of uses. The seeds contain between 40% and 60% oil that is rich in triglycerides, mainly ricinolein. The seed also contains ricin, a water-soluble toxin, which is also present in lower concentrations throughout the plant. Another plant with a bad reputation is the castor bean plant, Ricinus communis. This plant has had economic importance pretty much since the dawn of civilized time, yet because it can be used to prepare a toxin (ricin), there are people who think it should be made illegal (and in some places it is).  Toxic principle. The principle toxin of castor bean is ricin which is a lectin, also termed a toxalbumin. Ricin may comprise up to 3% of the seed weight. Toxalbumins are very toxic plant-derived compounds that combine carbohydrate and protein moieties or components. Description. Castor bean is a herbacious annual which can reach to nearly 15 feet tall when growing in open spaces in warm climates. Large leaves are alternate, palmately lobed with 5-11 toothed lobes. Castor beans, from which ricin is synthesized (Wikimedia Commons). Made from ordinary castor beans, ricin can be incredibly dangerous and even deadly -- if milled or processed right. The substance is called “very toxic” by the U.S. Centers for Disease Control and Prevention. Ricin is very difficult to process from the beans in which it is naturally found. It is a part of the waste “mash” produced when castor oil is made, according to the CDC, and if the beans themselves are chewed and swallowed, the released ricin can cause injury. Ricin is a natural, highly toxic compound that is one of the byproducts of processing castor beans. If inhaled, injected or ingested, less than a pinpoint of ricin can kill a person within 36 to 48 hours due to the failure of the respiratory and circulatory systems. There is no known cure.  The bean is the seed, however it is not really a bean. In this seed, there is ricin, a deadly toxin. The lethal dose for adults is 4 to 8 seeds, however reports of poisoning … are relatively rare. The symptoms of poisoning can be delayed up to 36 hours, but commonly it happens around 2-4 hours. 
http://www.gardenguides.com/130368-poison-castor-beans.html http://www.gardenmyths.com/castor-beans-are-they-poisonous/ https://en.wikipedia.org/wiki/Castor_oil_plant http://undergroundhealthreporter.com/fact-or-myth-is-the-castor-bean-plant-poisonous/ https://en.wikipedia.org/wiki/Castor_oil_plant http://chemistry.about.com/b/2008/04/10/castor-bean-plant-good-plant-with-a-bad-rep.htm http://www.library.illinois.edu/vex/toxic/castor/castor.htm http://www.foxnews.com/science/2013/04/29/how-deadly-is-ricin.html http://www.cnn.com/2013/04/16/health/what-is-ricin/index.html http://www.answers.com/Q/Are_castor_bean_plants_poisonous
is a castor beans venomous