Three new species of Cymbella (Bacillariophyta) from high altitude lakes, China

This paper describes three new Cymbella species from high altitude lakes of Hengduan Mountains region, southwest China. Cymbella heihainensis Li et Gong nov.spec. is similar to C. modicepunctata Krammer, C. asiatica Metzeltin, Lange-Bertalot et Li, Y., but differs from them in valve size, stigmata, raphe ending and also striae number. Cymbella shudunensis Li et Metzeltin nov. spec. is related to C. terrafuegiana, but differs in wider valve size, larger central area and coarser puncta. C. shudunensis differs from C. proxima Reimer in Patrick et Reimer group in reverse lateral raphes at the proximal endings, and distinguished from C. cistula (Ehrenberg) O.Kirchner group in the absent central area on dorsal side. Cymbella xingyunnensis Li and Gong sp. nov. resembles the group around C. proxima, and the most similar taxon is C. sinensis Metzeltn et Krammer,which can be distinguished by its lack of stigmata