Fig. 155. Quassia - Cross-section of wood.
(65 diam.) A, Water tube. B, Medullary ray. C. Wood fibers. (Photomicrograph.)
This image is from Quassia in Sayre's Manual of Organic Materia Medica and Pharmacognosy, 1917.
A herbal distance course
Henriette's herbal is one of the oldest and largest herbal medicine sites on the net. It's been online since 1995, and is run by Henriette Kress, a herbalist in Helsinki, Finland.