The Collaborative International Dictionary of English v.0.48:

Claytonia \Clay*to"ni*a\, prop. n. [Named after Dr. John
   Clayton, an American botanist.] (Bot.)
   An American genus of perennial herbs with delicate blossoms;
   -- sometimes called spring beauty.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Claytonia
    n 1: genus of mainly North American succulent herbs with white
         or pink flowers usually in terminal racemes [syn:
         Claytonia, genus Claytonia]