The Collaborative International Dictionary of English v.0.48:

capeweed \cape"weed\ n.
   1. a European weed (Hypochaeris radicata) widely
      naturalized in North America, having yellow flower heads
      and leaves resembling a cat's ears.

   Syn: cat's-ear, cat's ear, California dandelion, gosmore.
        [WordNet 1.5]

   2. [Cape, from the Cape of Good Hope, South Africa + weed.] a
      type of low-growing, creeping plant (Arctotheca
      calendulaceae), used as a ground cover in warm climates.
      --RHUD
      [PJC]

WordNet (r) 3.0 (2006):

capeweed
    n 1: European weed widely naturalized in North America having
         yellow flower heads and leaves resembling a cat's ears
         [syn: cat's-ear, California dandelion, capeweed,
         gosmore, Hypochaeris radicata]