Alocasia macrorrhizos (also known as Alocasia macrorrhiza) is also known as the 'Giant Elephant Ear'.  It is a fantastic specimen plant for that tropical look, and is also a great indoor plant.

It has large, glossy emerald green leaves 3-6 feet long, held stiffly upwards, with prominent veining on the underside of the leaves.  The plant will easily grow to 9 feet in good conditions in the ground.  If grown in a pot, it will not reach its full potential, but still expect at least 3 to 4 feet (or more) if your pot is large enough.

This is a very fast growing Alocasia.  In good conditions, a baby will reach the size in 4 feet in less than a year

Because it grows so fast, it is a great plant for those of you who have nice enough summers, but too cold winters.  You can grow it outdoors during the spring and summer, where it will reach its full size in a season.  Dig this up and bring it indoors for the winter, and then next year plant it back outdoors again. 

Alocasia macrorrhizos is reasonably cold hardy, and would be fine down to Zone 9, maybe even a bit colder in the right microclimate.  It tolerates a very mild frost.

Like all Alocasias, this plant requires warmth and humidity.  The soil should be rich but well drained, and the plant appreciates frequent watering (daily), especially in hot weather and as the plant grows larger.  However, if you live in a colder area, it is best to reduce watering during winter, particularly while the plant is smaller.  Too much water will rot the tuber.

It is easy to grow in either sun or in shade. Bright light is preferred, but it will do well in anything up to 80% shade.  The plants in the photos grow in full sun.

Once it gets big enough, it will start to produce offsets (baby plants) which can be easily transplanted.