Fig. 250. Pyrethrum.

—Cross-section of root. (11 diam.) A, Cork. B, Ring of stone-cells. C, Parenchyma of primary cortex. D, Cambium. E, Medullary ray. F, Xylem. (Photomicrograph.)

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