"The castor-oil plant (Ricinus communis). Portion of cross-section of young stem. co, Cortex; p, pith or medulla; e, epidermis; ph, phloem; ca, cambium; x, xylem. The last three elements compose the fibro-vascular bundle, the cambium being continuous from bundle to bundle; the portion between the bundles is called interfascicular cambium." -Gager, 1916

Castor-Oil Plant Stem

"The castor-oil plant (Ricinus communis). Portion of cross-section of young stem. co, Cortex; p, pith…