Defining Tubers and Rhizomes

Tubers and rhizomes share many similarities with true bulbs and corms, but they do have some key differences.

tuber
The potato is a typical tuber.

Tubers are modified stems with starchy interiors but no basal plate or tunic. Both roots and shoots sprout from the same growth buds, called eyes. The potato is a typical tuber. Tuberous roots are similar to tubers but are really swollen roots. Dahlias produce tuberous roots.

rhizome
Rhizomes grow in a horizontal direction.

Rhizomes are thickened underground stems. They grow in a horizontal direction, sprouting new sections as they go. The bearded iris (Iris germanica) has a typical rhizome.

Want more information about bulb gardens? Try these:
  • Planting Bulbs: Learn how to plant bulbs in your garden.
  • Bulb Garden Care: Find out the ins and outs of caring for a bulb garden.
  • Tips for Growing Bulbs: Check out tips for growing these unique plants.
  • Bulbs: Discover all you need to know about bulbs in this article.
  • Bulb Gardens: Learn how bulbs can create a lovely garden.
  • Gardening: We answer all of your general gardening questions in this section.