A new species of spikemoss from Yunnan Province of China, Selaginelladianzhongensis, is described and illustrated based on evidence from gross morphology, micromorphology and molecular phylogeny. S.dianzhongensis is most similar to S.amblyphylla in its habit of creeping stem, leaf size, and obviously dimorphic sporophylls, but is distinct by its ventral leaves ovate-oblong, subcordate at base, basiscopic base entire, axillary leaves ovate and decurrent at base. Molecular phylogeny analysis of three chloroplast gene regions (rbcL, atpI, psbA) shows that S.dianzhongensis forms an independent branch with strong support which is distantly related to S.amblyphlla and S.kurzii, but sister to S.bodinieri which is quite different in habitat of erect or ascending stem and rhizophores restricted to the lower part, and slightly dimorphic sporophyllus.
Keywords: Selaginella amblyphylla; Lycophytes; Yunnan; rbcL, atpI, psbA; taxonomy.