columella

noun

1. 1

   Any of various small structures in plants or animals that are columnar in shape.

2. 2

   The skin at the end of the septum which separates the nostrils.

3. 3

   (comparative anatomy) In birds, reptiles, and amphibians, the small bone which carries vibration from the tympanum to the inner ear.

4. 4

   In gastropods, the structure at the center of the whorls of the shell.

5. 5

   The structure at the center of the calyx where the septa join together.

6. 6

   The central sterile portion of the sporangium in various fungi.

7. 7

   A rod-shaped reinforcing element of the sexine layer of a pollen grain.