Castor Oil Plant - Part 2, Botanical facts and its uses

Did you know that Castor Oil Plant, Ricinus communis, the most imporatnt non-edible oil seed crop that belongs to Euphorbicea family, a native of India but now grown throughout the world with India producing and accounting for over three-quarters of the global yield?

The Castor oil plant with the Sanskrit eranda, also held to be ancient , probably pre - Aryan , in India, is not only a widely cultivated plant but is also seen growing in roadsides, vacant plots, and wastelands. It is perennial flowering plant in the spurge family, Euphorbiaceae. and is the sole species in the monotypic genus, Ricinus, and subtribe, Ricininae. Ricinus communis is the vegetable oil , the natural purgative, obtained by pressing the seeds of the castor oil plant.

Castor oil plant is a drought resistant plant that survives in adverse growing conditions, grows to a height of a tree 30 to 40m feet high in tropical and subtropical regions, but is mostly a fast-growing, suckering hardy shrub hardly growing to more than 4 to 5 feet high in temeparate climates in Europe and the Mediterranean Countries. As a branched annual herb it has thick hollow herbaceous stems which are cylidrical, smooth and shiny with a purplish blloom in the upper part. It is also cultivated as an ornamental plant. Breeders of this crop have selected a range of cultivars for leaf and flower colours, and for oil production. 

Its glossy leaves are simple of alternate shape, palmately 6-8-lobed, peltate, to 20 x 24 cm; lobes 9-15 x 3-6 cm, lanceolate, margin coarsely serrate, apex acuminate; petiole to 18 cm long. The flower

is unisexual (male and female) where both types are borne on the same plant (monoecious) in terminal panicle-like inflorescences of green or, in some varieties, shades of red. The fruit is capsule type, a spiny, greenish (to reddish-purple) containing large, oval, shiny, bean-like, highly poisonous seeds with variable brownish mottling. Castor seeds have a warty appendage called the caruncle, which is a type of elaiosome. The caruncle promotes the dispersal of the seed by ants (myrmecochory).The seeds contain between 40% and 60% oil that is rich in triglycerides, mainly ricinolein. The seed also contains ricin, a highly potent water-soluble toxin, which is also present in lower concentrations throughout the plant. Fruiting season is December to March. 

Castor oil plant, predominantly a herb, can be easily grown from seed. The seeds are explosively released when the fruit are mature, thereby aiding their spread. They are also often dispersed by floodwaters and animals (e.g. rodents and birds). Humans also spread the seeds in dumped garden waste, mud, soil and on vehicles and machinery.

The common name "castor oil" probably comes from its use as a replacement for castoreum, a perfume base made from the dried perineal glands of the beaver (castor in Latin). It has another common name, palm of Christ, or Palma Christi, that derives from castor oil's reputed ability to heal wounds and cure ailments.

Its chemical composition consists of volatile oils, flavonoids, apigenin, luteolin, quercetin, kaempferol, tiliroside, triterpene glycosides including euscapic acid and tormentic acid, phenolic acids, and 3%–21% tannins.The seeds contain between 40% and 60% oil that is rich in triglycerides, mainly ricinolein.

India is a leading producer of castor oil seeds accounting for over three-quarters of the global yield of 1,795,000 tons in 2021; in India Gujarat is the largest producer of this crop.

According to the Guinness World Records, this is the world's most poisonous common plant. Symptoms of overdosing on ricin, which can include nausea, diarrhea, tachycardia, hypotension and seizures, persist for up to a week. The poison can be extracted from castor by concentrating it with a fairly complicated process similar to that used for extracting cyanide from almonds. However, commercially available cold-pressed castor oil is not toxic to humans in normal doses, whether internal or external. It is a colorless to very pale yellow liquid with a distinct taste and odor. 

Castor oil is generally obtained by crushing the whole or decorticated seed in expellers, hydraluic presses, roraty mills, screw presses, village ghanies and domestic method of boiling. The oil content in the seeds range from 40-55%. 

Castor oil is an active ingredient with pale yellow, translucent texture and a mild odour. Castor oil has antimicrobial, anti-inflammatory and moisturising properties and thus, it is considered safe for skin and hair. Owing to this, castor oil remains a popular choice among consumers to naturally treat their common conditions like constipation as well as skin problems. Apart from this, it also finds major applications in the industrial sector for the processing of a wide variety of products.

Ayurvedic medicine in which the castor oil herb is used are:

Vishatinduka Taila, Maharasnadi kashayam, Chaturmukha ras, Eranda pak, Gandharvahastadi kashayam, Lohaasava. Castor oil has long been used on the skin to prevent dryness. Either purified or processed, it still is a component of many cosmetics. Castor oil is also used widely as a laxative.

- Narasipur Char