Poisonous Plants : Castor Plant

Castor plant, Ricinus communis, is a species of flowering plants in the spurge family, Euphorbiaceae. 

The name Ricinus is a Latin word for tick, for the resemblance of castor bean to certain ticks.  The specific name ‘communis’ comes from Latin word commun, which means “common”.

The  common name ‘castor oil’ comes from Latin word ‘castor’ for beaver, of which castor oil was used as replacement for castoreum, a perfume made from dried perineal glands of beavers.  Castor oil plant has another common name, palm of Christ, ‘Palma Christi’, that derived from its therapeutic oil.

Despite its name, castor bean is not a true bean.  Castor bean is the source of castor oil, as well as ricin, a lethal toxin.  Ricin is also present throughout the plant in lower concentration.

Originated from the Mediterranean Basin, castor plant is presently planted over the tropical regions.   Leading production of castor bean are : India, China and Brazil.  

Castor oil had been used since ancient time for its therapeutic value and as fuel for lamps.   It contain mostly ricinoleic acid, a prized monosaturated fatty acid.   Today, castor oil is used in food additives, flavoring, mold inhibitor, preservative, in addition to various modern drugs.  Castor oil derivatives are also used in manufacturing of soaps, lubricants, hydraulic fluids, brake fluids, paints, dyes, coatings, inks, cold resistant plastics, waxes, nylon, and perfumes.

  

Raw castor beans are however, famous for its lethal toxin ricin.  4 – 8 seeds alone can kill an adult human.  Despite this, suicides and murders involving ingestion of castor beans are unheard of in producing countries.   

If ricin is ingested, symptoms may begin within 2 – 4 hours, but may be delayed up to 36 hours.   Symptoms includes burning sensations in mouth and throat, abdominal pain, purging and bloody diarrhea.   

However, poisoning occurs only when ingested seeds are chewed.  Intact seeds may pass through digestive tract.

Commercially cold-pressed castor oil is not toxic to human in normal doses, either internally or externally.

Poisonous Plants : Cycas

Cycas is the only genus in the family Cycadaceae of about 95 species. 

The generic name ‘Cycas’ comes from Greek ‘Koikas’, which means “a kind of palm”, but they are not palms at all !

Cycas is native to the tropical regions of Old World.  It can be found in eastern Asia, south east Asia, eastern Africa, northern Australia, Polynesia, and Micronesia.

The best-known species are  Cycas revoluta, widely known as ‘King Sago’ and  Cycas rumphii, ‘Queen Sago ’.

Cycas are generally symmetrical, with a crown of shinny, light to dark green leaves. 

Trunk is about 20 – 40 cm in diameter, lengthens with age.  The trunk is very slow-growing. 

Cycas are very popular as ornamental plant.  However, there are reports that the plant is poisonous to animal if ingested.

Somehow, pets find the plant very palatable.  Basically, all parts of the plant are toxic.  The seeds, especially, contain the highest level of toxin cycasin.  Cycasin causes gastrointestinal irritation, and in high doses, leads to liver failure.  Other toxins include beta-methylamino L-alanine, a neurotoxic amino acid.

Clinical symptoms may include  vomiting, diarrhoea, weakness, seizures, liver failure, or hepototoxicity characterized by icterus, cirrhosis, and ascites.  The pet may appear bruised, have nose bleeds ( epistaxis ), blood in the stool ( melena ), bloody straining ( hematochezia ), and blood in the joints ( hemarthrosis ).

Even though Cycas are highly poisonous, starch extracted from it’s trunk is a less-common food source for some people of the Pacific and Indian Oceans.   The stem, root and seeds are grinded, and repeatedly washed to leach out the toxins, and then dried to produce a starch similar to palm sago.