Data from: Macromtrium longipapillosum sp. nov. (Bryophyta, Orthotrichaceae) from Japan, with comments on M. comatum

The new species Macromtrium longipapillosum D. D. Li, J. Yu, T. Cao & S. L. Guo from Japan is described and illustrated by line drawings and photographs. The new species can be distinguished from all congeners by the combination of the following features: 1) lanceolate to oblong-lanceolate leaves with obtuse, acute to broadly acuminate apices; 2) upper and median laminal cells with thin and inflated walls, with a single, large, occasionally forked papilla, 7–14 μm, occasionally up to 18 μm, 3) basal cells near costae forming a ‘cancellina region’, 4) inner perichaetial leaves ovate lanceolate, abruptly narrowed to a long acuminate upper part; 5) short and left-twisted seta; and 6) obloid capsules with well-developed exostome teeth. We also revise the circumscription of Macromitrium comatum Mitt. and discuss the relationships of M. comatum with M. longipapillosum and other relevant species.

本研究对产自日本的新种Macromtrium longipapillosum D. D. Li, J. Yu, T. Cao & S. L. Guo进行了形态描述，并辅以线条图与照片加以说明。该新种可通过以下特征组合与同属所有其他物种相区分：1）叶呈披针形至长圆状披针形，先端钝圆、急尖至宽渐尖；2）叶上部及中部细胞的细胞壁薄且膨大，具单个较大的乳突，乳突偶尔分叉，尺寸为7–14 μm，偶可达18 μm；3）近中肋的叶基部细胞形成「栅格状区域」；4）内雌苞叶呈卵状披针形，骤然收缩为长渐尖的上部；5）蒴柄短且呈左旋扭曲；6）孢蒴呈长圆形，具发育良好的外齿层齿片。本研究同时修订了Macromitrium comatum Mitt.的分类界定，并探讨了M. comatum与M. longipapillosum及其他相关类群的亲缘关系。