The Collaborative International Dictionary of English v.0.48:

Laserwort \La"ser*wort`\ (l[=a]"s[~e]r*w[^u]rt`), n. [L. laser
   the juice of the laserwort.] (Bot.)
   Any plant of the umbelliferous genus Laserpitium, of
   several species (as Laserpitium glabrum, and Laserpitium
   siler), the root of which yields a resinous substance of a
   bitter taste. The genus is mostly European.
   [1913 Webster]