Herbs & Plants

Colocasia (Bengali Kochu)

Botanical Name:Colocasia antiquorum
Kingdom: Planta
Division: Magnoliophy
Class: Liliopsida
Order: Alismatales
Family: Araceae
Common Names
: Polynesian Names: Kalo, Poi, Callaloo, Cocoyam, Dasheen, Eddo, Eddoe, Eddy Root, Tara, Tarro, Tarrow, Dalo, Kochu(in Bengali), English Names:Taro,Swamp Taro ,Elephant’s Ear
Habitat:India, Pakisthan, Bangladesh,Srilanka, Burma Philipines. Hawaii, Taro was probably first native to the lowland wetlands of Malaysia (taloes). Estimates are that taro was in cultivation in wet tropical India before 5000 B.C., presumably coming from Malaysia, and from India further transported westward to ancient Egypt, where it was described by Greek and Roman historians as an important crop.

Description:Colocasia is a genus of six to eight species of flowering plants .They are herbaceous perennial plants with a large rhizome on or just below the ground surface. The leaves are large to very large, 20-150 cm long, with a sagittate shape. The elephant’s-ear plant gets its name from the leaves, which are shaped like a large ear or shield.

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It is a herb with clusters of long heart- or arrowhead-shaped leaves that point earthward. Taro leaves grow on erect stems that may be green, red (lehua), black or variegated.
The new leaves and stems push out of the innermost stalk, unrolling as they emerge. The stems are usually several feet high. Taro bears a short underground stem called a corm, where the plant stores starch produced by the leaves. In the eight to sixteen months of its development, the corm can grow as large as six inches in diameter. People raise taro to obtain this valuable starchy root. When the plant reaches maturity, it will produce a flower stalk in some leaf axils. Near the apex of the flower stalk appears the yellow-white, tubular spathe, or modified leaf, which covers and protects the flower cluster within. Inside grows an erect spike called the spadix. The spadix bears two kinds of flowers: the male and the female flowers. The male flowers lie toward the upper part of the spadix, and the female flowers lie toward the lower part. Tiny new plants appear around the base of the root corm.

Click to see different pictures of Colocasia esculenta , Taro ,Kalo

Species of Colocasia:

* Colocasia affinis (syn. C. marshallii)
* Colocasia bicolor
* Colocasia coryli
* Colocasia esculenta (syn. C. antiquorum) – Taro or Elephant-ear
* Colocasia fontanesii
* Colocasia gigantea – Giant Taro
* Colocasia lihengiae
* Colocasia macrorrhiza
* Colocasia menglaensis

Colocasia species are used as food plants by the larvae of some Lepidoptera species including Palpifer murinus and Palpifer sexnotatus.

Cultivation and uses:

Colocasia esculenta and other members of the genus are cultivated for their edible tubers, a traditional starch staple in many tropical areas. The edible types are grown in the South Pacific and eaten like potatoes and known as taro, eddo, and dasheen. This famous root vegetable is known as “Arbi/Arvi” in the Indian subcontinent where its leaves are also cherished. A favorite Hawaiian dish is made by boiling the starchy underground stem of the plant” (World Book Encyclopedia).

In Dakshina Kannada and Udupi districts of Karnataka state (India), they are used to make Patrode – a popular delicacy; in Kerala state (India) they are used to make chembila curry – a tasty delicacy. The stem & root are also used in the preparation of delicacies ( ishtu moru curry etc.). In Andhrapradesh state of India, several delicacies are made either with root or leaves of Chaama. In Gujarat, they are used to make a popular dish called Patra. They are grown outside year-round in subtropical and tropical areas. In temperate regions, they are grown as ornamental plants, planted out for the summer and dug up and stored over winter; they can be grown in almost any temperature zone as long as the summer is warm. The plant can be grown in the ground or in large containers.

The root tuber is typically planted close to the surface. The first signs of growth will appear in 1 to 3 weeks. The adult plant will need a minimum of at least 1m of space for good growth. They do best in compost-rich soil and in shade, but will grow reasonably well in average soil provided it is moisture-retentive. The plants should not be left to go dry for too long; if this does happen, the leaves will wilt; watering will allow the plant to recover if done before they get too dry. Periodic fertilisation (every 3 to 4 weeks) with a common plant fertiliser will increase yields.

Its primary use, however, is the consumption of its edible corm and leaves. In its raw form the plant is toxic due to the presence of calcium oxalate, although the toxin is destroyed by cooking and the presence of needle-shaped raphides in the plant cells. However it can be rendered palatable by cooking, or by steeping in cold water overnight.

Corms of the small round variety are peeled and boiled, sold either frozen, bagged in its own liquids, or canned. The leaves are rich in vitamins and minerals.

It is also sold an ornamental aquatic plant.

Growth is best at temperatures between 20°C to 30°C. The plants can be damaged if temperatures fall below 10°C for more than a few days. When cultivated in climates with colder winters, the tuber must be dug up and stored during the colder, winter months in a cool, dry place protected from frost and with good ventilation to reduce the risk of fungal diseases. Replanting in spring is done when the chance of frost has passed.

Leaves and tuber of this plant are used as food items in the Indian subcontinent. The plant is known as Arabi or Ghuiya in local language as well as Patra.

Medicinal Uses:
The following are a few of the medicinal uses of poi and the Kalo plant. Poi is used to settle the stomach.
Mixed with ripe Noni fruit, it can be applied for boils. Poi can be mixed with pia (arrowroot starch) and taken for diarrhea. Some infections respond to the use of Taro leaves mashed with Hawai’i salt. This poultice can be applied to an injury, covered and wrapped with a large Taro leaf.
Undiluted poi is sometimes used as a poultice on infected sores. A piece of Taro stem, haha, can be touched to the skin to stop surface bleeding. For a sting from an insect, the stem leaf (petiole) can be cut and rubbed on the afflicted area, preventing swelling and pain.
(Whistler,W.A. 1992. Polynesian Herbal Medicine.)
The raw juice of Taro could be mixed with other juices to reduce fever. Also as a cure for thrush (‘ea), the Hawaiians grated the corm and mixed it with the ash of burnt coconut (niu) meat.
(Lucas, L. 1982. Plants of Old Hawaii.)
The following preparation was regularly used as a laxative: the scraped inside of a peeled Taro is mixed with the juice of white sugar cane, the meat of one fully matured coconut and two ripe Morinda citrifolia (noni) fruits. The mixture is then strained with the fiber of the Cyperus laevigata. The dose is taken five times in succession.
(Kaaiakamanu,D.M. and Akina,J.K. 1922. Hawaiian Herbs of Medicinal Value.)
In Fiji a decoction of the leaves with the scraped root of yasi yasi (Syzygium effusum) is drunk to treat stomach disorders. A decoction of the shredded leaves is drunk to promote menstruation while a decoction of the leaves and those of wabula (Merremia peltata) is used for the treatment of cysts, while the sap of the leaf stalk is used to treat conjunctivitis. The scraped steams of dalo and those of mulomulo (Thespesia populnea), kavika (Syzygium malaccense) and titi (unidentified) are added to a little water to provide a drink to encourage young children to eat when there is a loss of appetite.

Before Taro can be eaten, all parts of the plant must be cooked, in order to break down the needle-like calcium oxalate crystals present in the leaves, stem and corm. These crystals could be extremely irritating to the throat and mouth lining, causing burning and stinging sensation.
Scientific Research:
The young leaves of Taro are rich in vitamin C and the roots are rich in a starch composed of amylase (28%) and amylopectin (72%). Taro contains thiamine (vitamin B1), riboflavin (vitamin B2), niacin, oxalic acid, calcium oxalate and a sapotoxin.
The tubers contain aminoacids and high molecular weight proteins which inhibit human salivary (and the porcine) pancreatic amylases. The corms contain the anthocyanins pelargonidin 3-glucoside, cyaniding 3-rhamnoside, and cyaniding 3-glucoside. Hydroxycinnamoyl amides have been obtained from the inflorescences and two new dihydroxysterols have been isolated from the tubers.

The information presented herein is intended for educational purposes only. Individual results may vary, and before using any supplements, it is always advisable to consult with your own health care provider.