The Collaborative International Dictionary of English v.0.48:

Saltwort \Salt"wort`\, n. (Bot.)
   A name given to several plants which grow on the seashore, as
   the Batis maritima, and the glasswort. See Glasswort.
   [1913 Webster]

   Black saltwort, the sea milkwort.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Batis maritima
    n 1: low-growing strong-smelling coastal shrub of warm parts of
         the New World having unisexual flowers in conelike spikes
         and thick succulent leaves [syn: saltwort, Batis
         maritima]