Source : Webster's Revised Unabridged Dictionary (1913)

Cudweed \Cud"weed`\ (k?d"w?d`), n. [Apparently fr. cud + weed,
   but perh. a corruption of cottonweed; or of cut weed, so
   called from its use as an application to cuts and chafings.]
   (Bot.)
   A small composite plant with cottony or silky stem and
   leaves, primarily a species of {Gnaphalium}, but the name is
   now given to many plants of different genera, as {Filago},
   {Antennaria}, etc.; cottonweed.

Source : WordNet®

cudweed
     n 1: any of numerous plants of the genus Gnaphalium having
          flowers that can be dried without loss of form or color
     2: any plant of the genus Filago having capitate clusters of
        small woolly flower heads [syn: {cotton rose}, {filago}]
     3: perennial cottony-white herb of southwestern United States
        [syn: {western mugwort}, {white sage}, {prairie sage}, {Artemisia
        ludoviciana}, {Artemisia gnaphalodes}]