Veratrum. Fig. 4. One of the bundles of the rhizome

Fig. 4.—One of the bundles of the rhizome, as seen in cross-section, magnified 370 diameters.
a, cell of parenchyma exterior to bundle;
b, cell of endodermis;
c, scalariform tracheid in xylem;
d, phloem tissues occupying centre of bundle.

This image is from Structure of Veratrum viride in the April issue of the American Journal of Pharmacy, 1895.