The Collaborative International Dictionary of English v.0.48:

Sandwort \Sand"wort`\, n. (Bot.)
   Any plant of the genus Arenaria, low, tufted herbs (order
   Caryophyllaceae.)
   [1913 Webster]

WordNet (r) 3.0 (2006):

sandwort
    n 1: loosely matted plant with moss-like foliage studded with
         tiny starry four-petaled white blossoms; mountains of
         central and southern Europe [syn: sandwort, Moehringia
         mucosa]
    2: low-growing herb having clusters of small white four-petaled
       flowers [syn: sandwort, Moehringia lateriflora]
    3: low-growing chiefly perennial plant usually with small white
       flowers suitable for e.g. rock gardens