摘 要 ：报道真藓科（Bryaceae）直齿藓属（Orthodontium）一新种，具边直齿藓 O．bilimbatum X．J. Li et D．C．Zhang。本种主要特征（l）蒴齿双层，内齿长，狭线形，无基膜。（2）叶边缘明显分化，具2～3列狭长细胞，除近尖部和基部边缘外，明显两层。（3）叶细胞明显宽于本属各种（宽达18～24 um）。（4）蒴盖短圆锥形，无长喙状尖；本种介于Orthodontium与Orthodontopsis两属之间，根据蒴齿双层之重要特征，应隶属于前者，又因其独具以上特征，故在该属下建立一独立的新组，即Section Bilimbatum，本种即为该组模式。原模式存昆明植物研究所隐花植物标本馆。
Abstract:The genus Orthodontium of the family Bryaceae is newly reported from Yunnan, China. The O. bilimbatum X. J. Li et D. C. Zhang as a new species, found in the Mt. Meilixueshan, Northwestern Yunnan, China, is described in Latin and illustrated in this paper. It is of main characteristices of (1) the double peristomes being not in well-development, (2) bistratose leaf borders, consisting of 2- 3 rows of elongate-linear thick-walled cells which occur on all leaf margins except for the apices and proximal bases, (3) the cells in middle of leaf 60~ l00 um long and l8~ 24 um wide, (4) opercule short conical without beak on it. The characteristics of the new species are between genera of the Orthodontium and Orthodontopsis. With double peristomes as an important character of Orthodontium on taxonomy, the new taxon should be classified into the genus. In addition, 2, 3 and 4 characters men- tioned above are special in this genus, so a new Section Bilimbatumis proposed. The specics as a holotype of the new section is deposited in Cryptogamic Herbarium, Kunming Institute of Botany,Academia Sinica(HKAS).