Abstract: A new subtribe of the family Urticaceae, Sphaerotylinae C. J. Chen, a new genus, Sphaerotylos C. J. Chen and its type species S. medogensis C. J. Chen from south-eastern Xizang (Tibet) in China are described and illustrated. The subtribe is regarded as a primitive group in the tribe Boehmerieae. The ring-shaped stigma and the ball-like connective are the first discovery in the family Urticaceae. The types of the stigma of the family, their taxonomic significance and their evolution are also discussed in the present paper.

Key words: Urticaceae, Trib.Boehmerieae, Subtrib.Sphaerotylinae, Gen.Sphaerotylos, S.medogensis, circular stigma, ball-like connective, Urticaceous stigma