Fig. 019. Cross-section of couch-grass.

Fig. 19. Cross-section of couch-grass.

a. Medullary parenchyma.
b. Woody tissue.
c. Wood-bundles.
d. Cortical parenchyma.

This image is from Triticum in Sayre's Manual of Organic Materia Medica and Pharmacognosy, 1917.