Colocasia is a genus of six to eight species of flowering plants in the family Araceae, native to tropical Polynesia and southeastern Asia (Wagner, Herbst, and Sohmer, 1999). Common name "Elephant-ear", or "Taro" - this name is also used for some other large-leaved genera in the Araceae, notably Xanthosoma and Caladium.
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.Species of Colocasia
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 Goa they are known to make Pattoe - a well-known delicacy. 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.
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.