The Collaborative International Dictionary of English v.0.48:

Marattia \Marattia\ prop. n.
   The type genus of the Marattiaceae, consisting of ferns
   having the sporangia fused together in two rows.

   Syn: genus Marattia.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Marattia
    n 1: type genus of the Marattiaceae: ferns having the sporangia
         fused together in two rows [syn: Marattia, genus
         Marattia]