Alocasia macrorrhiza: Giant taro

Family: Araceae
Common name: Giant taro, Giant elephant ears, Giant alocasia, Biga, Pia

Giant taro plants can transform your garden and give it an exotic, tropical look with their large, green, elephant ear-shaped leaves. They are mostly grown as ornamental plants growing to a height of 4-5 meters under ideal conditions, but most houseplants only grow 1-2 meters.

The stem is short with many large leaves arising from it. Leaves are broad, dark green and glossy pointing upwards forming an almost straight line with the petioles. Petiole is thick and stout, continuing as a prominent midrib along the center of the leaf, and about 1 meter long.

The plant produces underground corms that are edible, but are not generally used since it contains large amounts of raphides which is toxic to humans. Even leaves contain these raphides or calcium oxalate crystals, which can cause skin irritation on contact.

The corms are eaten in some parts of the world, but after multiple rounds of cooking to ensure that the toxicity is completely removed.

Alocasia is closely related to other species like Taro or Colocasia esculenta, Arrowleaf elephant ear or Xanthosoma sagittifolium and Yam or Amorphophallus paeoniifolius. All of these plants are cultivated for their edible roots, which are popular in Indian cuisine.

But Alocasia are mostly grown as ornamental plants in gardens, parks and landscaped areas. They can also be grown indoors, provided they are placed near sunny windows. These plants also need good humidity and well-drained soil.

Overwatering Alocasia plants can result in root rot and yellowing of leaves; underwatering can result in browning and drooping of leaves. Since these plants grow very quickly, make sure they have enough space around them. If Alocasia are grown in pots, you will have to repot them once the plant is too big for its pot.

Alocasia plants produce flowers which have a long spadix and large petal-like spathe enclosing it. The spadix contains the male and female flowers, and can later form small red berries containing pale brown seeds that are about 4 mm in diameter. There is a variant called ‘Black Stem’ characterized by black petioles and dark green leaves.

In spite of its toxicity, the plant has many medicinal uses, in treatment of fever, malaria, diarrhea, typhoid, tuberculosis, snake bites, insect bites, burns and stomach pain. Alocasia root is used in treating stomach ailments. Leaves are used to treat cuts, burns, wounds and rheumatic pains. But always remember that the plant has a high level of toxicity; so it is better to keep kids and pets away from them.

Propagation is through tubers.