Application of microscopy in authentication of traditional Tibetan medicinal plant Halenia elliptica

Halenia elliptica D. Don, a popularly used ethnodrug from Qinghai-Tibetan plateau, was studied to reveal the indispensable morphoanatomic details. The fixed, sectioned, and stained plant materials as well as the epidermis, powder, and maceration materials were studied using light microscope according to the usual microscopic techniques. The results of the microscopic features were systematic described and illustrated. In the root, an endodermal cell was divided into 8-16-22 and 38-50-62 daughter cells in transverse section and in face view, respectively, and 9-11-13 phloem strands were present in primary structure; in the stem, stone cells were observed in the cortex, pericycle, and external phloem while 17-19-21 internal phloem strands were present in an incontinuous ring; in the pedicel, 8-10-12 internal phloem strands were observed to form an incontinuous ring; anisocytic and anomocytic stomata were present in leaf and sepal epidermis; pollen grain was with three germinal apertures and furrows; a few tracheids, a large number of spiral vessels, and various fibers were observed. Also, semiquantitative and quantitative micrographic parameter tables were simultaneously presented. Further, the key authentication parameters were concluded. The study indicated that light microscopy and related techniques could be unambiguously applied to the authentication of Halenia elliptica.