There Are Bulb Imposters Among Us

Another bulb imposter is a rhizome. It is actually a stem that grows horizontally under the ground.

Why is it called a stem and not a bulb?

It's because a stem has nodes and internodes. On a rhizome, the little dimples or sunken areas are the nodes and the spaces between them are the internodes. Rhizomes include ginger, iris, asparagus and lily of the valley.

See if you know the difference between a bulb and a tuber in Mystery #4.