The Collaborative International Dictionary of English v.0.48:

Stonecrop \Stone"crop`\, n. [AS. st[=a]ncropp.]
   1. A sort of tree. [Obs.] --Mortimer.
      [1913 Webster]

   2. (Bot.) Any low succulent plant of the genus Sedum, esp.
      Sedum acre, which is common on bare rocks in Europe, and
      is spreading in parts of America. See Orpine.
      [1913 Webster]

   Virginian stonecrop, or Ditch stonecrop, an American
      plant (Penthorum sedoides).
      [1913 Webster]