_Canker or Brier Rose_ (Vol. vii, p. 500.).--I suspect that this term
refers to the beautiful mossy gall, so commonly seen on the branches of the
wild rose, which has been called the _bedeguar_ of the rose. This is the
production of a cynips; and, from its vivid tints of crimson and green,
might well pass at a short distance for a flower, brilliant, but scentless.
Hence Shakspeare's allusion:
"The canker-blooms have full as deep a dye
As the perfumed tincture of the roses."