Abstract: Different opinions regarding the systematic position of Polygonum ciliinerve (Nakai) Ohwi persist in Flora Reipublicae Popularis Sinicae and some provincial floras. The vegetative and reproductive organs of P. ciliinerve were observed using scanning electron microscopy, paraffin sectioning and leaf epidermis isolating methods. The results showed that the main medicinal part of P. ciliinerve was a stem tuber, which originated from an axillary bud on the creeping stem, rather than a root tuber as previously suggested. The leaf upper epidermal cells were nearly oblong in shape; the lower epidermal cells were superficially wavy. Numerous papillae were present on both sides of the leaf veins, and a few of glandular hairs were dispersed on the leaf epidermis of both sides. The transverse sections of main leaf veins and petioles showed 5 and 10 vascular bundles respectively. The pericarp micromorphology showed fovea surface ornamentation. The transverse section of the seed was nearly triangular in shape. These characteristics of P. ciliinerve were obviously different from those of P. multiflorum Thunb. As a result, we suggested that P. ciliinerve should be treated as a species rather than a variant of P. multiflorum.

Key words: Ploygonum ciliinerve, organ, anatomy, stem tuber, stem tuber, systematic position