Sanguinaria. Fig. 3.—Small portion of longitudinal section

through xylem of a bundle, showing the reticulate ducts composed of short, irregular cells.
a, parenchyma cell containing starch;
b, one of the cells of a duct;
c, aperture communicating with next cell of the series, forming a duct. Magnification 330 diameters.

This image is from Some further observations on the structure of Sanguinaria canadensis in the American Journal of Pharmacy, 1895.