Anatomy of the underground parts of four Echinacea-species and of Parthenium integrifolium

Improved descriptions and detailed drawings of the most important anatomical characters of the roots of Echinacea purpurea (L.) MOENCH, E. angustifolia DC., E. pallida (NuTT.) NUTT., and of Parfhenium integrifolium L. are presented. The anatomy of the rhizome of E. purpurea, which was detected in commercial samples, and of the root of E. atrorubens NUTT., another known adulteration for pharmaceutically used Echinacea-species, is documented for the first time. The possibilities and limitations of the identification by means of microscopy are discussed. The anatomical differences between the roots of E. angustifolia, E. pallida and E. atrorubens are not
sufficient for differentiation, however, root and rhizome of E. purpurea and the root of Parthenium integrifolium appear well characterized. Because of the highly similar anatomy the microscopic proof of identity and purity of crude drugs of Echinacea must be done with uncomminuted material and the examination of cross sections.