Anther wall formation, sporogenesis and gametogenesis of Tripterospermum chinense (Gentianaceae), with emphasis on uniformity of characters in Tripterospermum and its systematic values

Tripterospermum sensu T.N.Ho comprises two sections that are readily discriminated morphologically. In the present paper, embryological characters in anther wall formation, sporogenesis and gametogenesis of Tripterospermum chinense, a member of sect. Platyspermum, are reported. Comparisons based on available data show that as far as the two recognized sections are concerned, embryological characters are uniform in all aspects, disapproving of the splitting of the genus into two sections. The notable differences between Tripterospermum and closely related genera support the phylogenetic conclusion that Tripterospermum is monophyletic.