To crop up

from The Collaborative International Dictionary of English v.0.48

Crop \Crop\, v. i.
   To yield harvest.
   [1913 Webster]

   {To crop out}.
   (a) (Geol.) To appear above the surface, as a seam or vein,
       or inclined bed, as of coal.
   (b) To come to light; to be manifest; to appear; as, the
       peculiarities of an author crop out.

   {To crop up}, to sprout; to spring up; to appear suddenly.
      "Cares crop up in villas." --Beaconsfield.
      [1913 Webster]