The stem of the fern plant. This may creep along or under the ground or even up a tree (a creeping rhizome), it may grow into a short or tall trunk (a vertical rhizome), or it may be a solid mass that gives rise to a tuft of fronds (an erect rhizome). Very often, the rhizome grows underground. The rhizome produces roots and new fronds.
Image acknowledgements: The University of Waikato Te Whare Wānanga o Waikato, Museum of New Zealand Te Papa Tongarewa