Source : Webster's Revised Unabridged Dictionary (1913)

Pearlwort \Pearl"wort`\, n. (Bot.)
   A name given to several species of {Sagina}, low and
   inconspicuous herbs of the Chickweed family.

Source : WordNet®

Sagina
     n : small low-growing annual or perennial herbs of temperate and
         cool regions [syn: {genus Sagina}]