Ponceau refers to poppies ot the red color of poppies - not the 
orange "poppyseed" poppies but the redder variety.  (In the US, 
people wear paper "poppies" of this color on Veterans Day).

There are many dyes with the word ponceau in their name and 
consequently much confusion in the histological literature as to 
which is called for in a particular stain.  Always refer to the CI 
number when ordering to avoid a serious mistake, as the commercially 
available ponceau dyes certainly are not interchangeable.  Ponceau de 
xylidine is probably the most famous, as it was used in some of the 
original trichromes.  It's exact identity is unknown (and quite 
possibly no longer made); ponceau 2R (CI 16150) is thought to be the 
most likely equivalent.

Dick

-- 
Dick Dapson
Anatech Ltd.
1020 Harts Lake Road
Battle Creek, MI  49015
800-ANATECH (800-262-8324)
email@anatechltdusa.com
Web address:  anatechltdusa.com