Word Study
cudweed
CIDE DICTIONARY
cudweed, 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.].
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. [1913 Webster]
OXFORD DICTIONARY
cudweed, n. any wild composite plant of the genus Gnaphalium, with scales and round flower-heads, formerly given to cattle that had lost their cud.
For further exploring for "cudweed" in Webster Dictionary Online