Abstract: First,Iris subdichotoma Y.T.Zhao was put in SubgenPardanthopsis (Hance) Baker in 1985 as its appearance is similar to Idichotoma Pall.,and then it was moved into SubgenCrossiris Spach by Dong et al.in 1999,when a clear crested appendage on outer perianth was noticed from other materials.But we prefer to regard it as a member of SubgenNepalensis (Dykes) Lawr.by reasons of possessing slender residues of withered leaves at its base,short rhizome,scape arising beyond basic leaves,blooming habit,sculpture of pollens.In addition,a white flower form of Isubdichotoma was found in wild.

Key words: Iris subdichotoma；Flower morphology；Taxonomic position