Knop

n.
  1. A knob; a bud; a bunch; a button.
  2. (Arch.) Any boldly projecting sculptured ornament; esp., the ornamental termination of a pinnacle, and then synonymous with finial; -- called also knob, and knosp.
    3. Knop sedge (Bot.),
    the bur reed (Sparganium); -- so called from its globular clusters of seed vessels.