Diospyros villosa root botanical identification

Diospyros villosa L. (de Winter) var. villosa (Ebenaceae) is an African shrub, which naturally occurs in Mozambique. Roots of D. villosa are used in the local traditional medicine as cathartic remedy for stomach and intestinal complaints [1]. The present work aims to establish botanical criteria to determine most relevant morphological roots features. Methodology includes microscopic and macroscopic analysis of transversal and long-cross section of entire, fragmentized and powdered plant material by light and scanning electron microscopy techniques. Quantitative microscopy studies were also performed. The most useful microscopic characters for roots identification purposes as herbal drug are: periderm composed of cork with 5 to 7 layers of tangentially elongated rectangular cells and few layers of phellogen and phelloderm; cortex with 6 to 8 layers of parenchymatous cells with frequent groups of 8 to 10 sclereids, oval to elongate in shape, crystalliferous brachysclereids with a short roughly isodiametric form and prismatic calcium oxalate crystals to go around; tanniferous cells (detected by histochemical reaction with potassium dichromate) and some cells with irregular cavities filled with quinones (detected by histochemical reaction with Börntraeger reactive) present in the cortical parenchyma; phloem crossed by uniseriate medullar rays and prominent xylem with bordered pitted vessels; numerous single and composed starch grains occur on the cortical parenchyma, inside the medullar ray cells and into the medullar parenchyma. Fragments of the above mentioned structures have also been observed on the powdered material. Obtained morphological characters allowed the D. villosa root identification and should be included in a future pharmacopeia monograph.

References: 1. Hutchings A et al. (1996) Zulu Medicianl Plants. University of Natal Press. Pietermaritzburg.