Anatomy of the leaf and bark of Warburgia salutaris (Canellaceae), an important medicinal plant from South Africa

• Combinations of anatomical characters are of diagnostic value
• Scattered large druse crystals and numerous small ones are present
• Bark has secretory cells, druses and parenchyma cells with brown contents
• Thin-walled fibre-like sclereids are present
• Sieve tubes have compound sieve plates on the lateral and oblique cross walls

Bark and leaves of Warburgia salutaris are commonly used in traditional and modern herbal medicine but there are no published anatomical descriptions that can be used in pharmacognosy or in comparative anatomy. Descriptions of salient features are presented, showing that a combination of anatomical characters is of diagnostic value. Leaf material can be identified by the absence of trichomes and the presence of translucent secretory cells, thick adaxial cuticles, numerous small druse crystals in the epidermal cells, scattered large druses and mesophyll cells with brown contents. Bark is similarly characterized by the combination of secretory cells, druses, parenchyma cells with brown contents, thin-walled fibre-like sclereids and compound sieve plates located on the lateral walls and oblique cross walls of the sieve tubes.