Genesis of microspore and the development of male gametophyte in Tripterospermum discoideum Tissue culture of Tripterospermum discoideum NOTES ON GENTIANACEAE FROM SOUTH CHINA Surface features of seeds in Tripterospermum and Crawfurdia (Gentianaceae) Embryology of Tripterospermum cordatum(Gentianceae) Phylogeny of Metagentiana and related genera (Gentianaceae) inferred from nuclear ribosomal ITS sequences New plants from limestone regions of Guangxi, China Embryogenesis of Tripterospermum discoideum